Latin was not easy. I have let myself grow rusty since the fall semester ended, and I was far from being the best student in the class. However, I learned a lot of things not only about latin, but about learning latin. There are things I would do differently. I don't consider these tips to be end-all be-all advice to be adhered to dogmatically -- however, this is what helped me specifically and personally, and some of this advice I didn't discover until well into the second semester.
Make a handbook of just forms
Of all the advice I am going to give, this the most important. I cannot stress the usefulness of this. Get a little notebook, and write out all the tables of forms, one after another, without any filler text between them. In the textbook, they are scattered throughout the chapters, with a bunch of text between them. If I want to look up the third declension neuters, for example, being able to find it quickly and easily saves me a bunch of time -- especially if I am constantly flipping between all five declensions, looking up passive verbs, and so forth, while translating. There are a multitude tables of inflections for various purposes -- five declensions, three demonstratives, personal pronouns, relative pronouns, infixes, passive verbs, participles, and so forth. I have them all in a little notebook dedicated strictly and solely for the purpose of just having these tables within.
Get them down precisely, in clear handwriting, and make sure to pay attention to long vowels. Next, get a blank notebook, and write these forms down over and over and over and over. Fill page after page just copying these forms. Leave it for a few hours, and then come back and try to pull them from memory, using the book to check yourself. Leave it again overnight, and then try to write them from memory the next day. This works so much better than just reciting them and checking the book each time. Copy copy copy. It was huge help to me. I actually filled an entire notebook this way.
Use flashcards you can get on your phone
"Physical flashcards are better" is an idea that actually set me back. They are more fun, and tactile, but using Quizlet on my phone allows me to drill cards while I'm eating dinner, on the toilet, in a waiting room, waiting for someone to show up, in the passenger seat. Yes, I could drill physical flashcards in all these locations, but come on, touching paper while you're eating spaghetti is just so much more of a hassle than a phone. If you're in a waiting room, having piles of flashcards is so much clumsier if you're just doing it on your lap. Quizlet lets you sort them into "unlearned" and "learned" piles, and to break them up so that you only study specific cards in the set.
Additionally, you may not have your flashcards always on your person, but your phone is most likely always with you. This makes it easier to study if you forget your cards.
There are plenty of other flashcard applications. I do not advise you to use Quizlet specifically (though Quizlet is my favorite), anything that you can do on your phone will be of use.
Duolingo
Third, use supplementary material. Duolingo is great, because it will give you practice in identifying declensions. You will have to do very small bite-sized translations. My professor told me that Duolingo is unhelpful "because it doesn't teach you what you need to read, it teaches you what you need to have a conversation, which is not the type of writing you will encounter in Classical Latin." This may be true, but it helped me get into the habit of figuring out, "okay, that's accusative, and that's genitive, so this must be the subject, and this verb must be attached to this word, etc etc etc". Also, it can't hurt to have extra vocabulary.
I may be biased in favor of Duolingo, because I have their premium subscription and use it competitively (I had to fight really hard for first place in the Diamond league.) It's a lot of fun to see what friends are learning, to get XP points from doing lessons, to see my place on a leaderboard, to get achievements, and so forth. I made the mistake of only starting the Latin course on Duolingo in my last couple of weeks of the semester. If I could go back in time, I would start the Duolingo course my first day of Latin. Currently, I'm just over halfway done with the course. Over winter break I studied Esperanto because I'm stupid.
Take advantage of online declension guides
If you encounter a word that you don't know, you can easily punch it into a website that will list the full declension of the word. For example, if I punch in the word "moneo", I get tables of forms for the indicative present, perfect, imperfect, pluperfect, future, future perfect, as well as subjunctive, imperative, infinitive, participle, gerundive. It lists 77 different forms of the word. This was ESSENTIAL for me when translating Cicero. Some words were super easy to see the form without help, but these guides were very good for double-checking. I never managed to memorize the forms of the relative pronoun (seriously, why does a pronoun need forty forms??), so determining which forms it could be was helpful in demystifying the sentence.
The guide I used was https://www.online-latin-dictionary.com, but I know others exist.
If you take a class, ask a ton of questions
I asked more questions that anyone else in my class. Did people find it obnoxious? Maybe. But I paid the university $3,000 USD to take Latin. If I pay several thousand dollars, I am going to get my money's worth. If I don't understand something, if I am confused, if I need help, I am going to raise my hand and get clarification. I am not going to let my money go to waste. I also approached the professor after class and asked questions. I don't think I would have passed the class if I didn't ask him questions. I'm serious, it was absolutely vital to my comprehension.
Additionally, he gave me good advice after class: "instead of reading the declension tables repeatedly, write them out", "translate the assigned reading before class, don't do it in class", "if you want to read the Vulgate, find some commentaries." Good advice, and I got it at no extra cost just by approaching him after class. He invited me into his office once and we talked for a while.
Read and translate from Latin
This was easy for me, because in my class we had a book of latin texts to accompany the textbook. If you don't have something like that, I HIGHLY recommend you find something easy to read, and try your best to translate it without google translate or outside help. Catullus was my favorite thing to translate. Translating is what really cemented all my knowledge into my head. Translating Cicero was a very unpleasant experience, it took forever, but it was still helpful. Learning all the forms is useful, but you don't learn how to spot hte forms and parse the sentence without trasnlation. It is the only way to learn those skills.
Conclusion
People say Latin is a cakewalk compared to Greek. A lot of the vocabulary just makes sense, like "conservo" meaning "protect", "labor" meaning "work", "poeta" meaning "poet", and so forth. I'm trying to get to the point where I can read the Latin Vulgate without help, and maybe Catullus too. Right now my plan is to drill like the 20 tables I had to learn. Once I know them all super well, I am going to brush up on the ablatives. And then, it is vocab time!
Once I get to a point where I'm comfortable with my Latin, I plan to move on to another dead language. My current writing project is almost a historic novel at this point, with how Celtic is has become. I think it's appropriate for me to try Old Irish (also known as Old Gaelic), which is supposedly a similar language grammatically. However, they say Manx is easier to learn, more similar to English grammatically and also has some loanwords. Welsh was also on the table, but Welsih is a Brittonic language, while Irish is a Gaelic language