It's been a long time since I learned, and I had the benefit of learning at school. With so much expert advice here, I feel somewhat diffident about offering more than encouragement. Which said, I'd say five things:
1. If you need to, brush up on your English grammar as you work through Latin. It's hard to understand what the grammar books say if you are not confident about distinctions between, say, adjectives and adverbs, or not sure what a participle is.
2. Remember that learning a language is not an exercise in decoding. You have to treat Latin as a language not a cipher. Read it out loud, however stupid you feel doing so. (Don't worry overmuch about accent or pronunciation.) Always read a whole sentence before you begin to translate, maybe a few times. If you just try to translate each word and then put it together you will never see the language as more than a code.
3. Especially if you are learning on your own, be religious about doing every exercise properly. Always write out the answers. Always correct them. Always be rigorously harsh on yourself about mistakes. Use exercises diagnostically: if you keep making mistakes of one sort, go back and revise the topic that is causing trouble. If you did an exercise badly, go back to it a few days later and try it again.
4. Don't just read grammar books. To read Latin easily you need to acquire a certain amount of cultural knowledge (about history, mythology, ordinary life). Reading books in English about these things will enrich your Latin learning (and vice versa), and help you to stay motivated.
5. It's not a race. It may well take you some time to feel comfortable with Latin. Work slowly and methodically, but not so slowly that you lose interest. Revise often. Keep reminding yourself how much you have learned, rather than thinking about how much you have left to learn. But as soon as you feel able to do so begin to have a shot at simple bits of real Latin prose or verse. (Caesar and Ovid were traditional school examples of places to start; but others here can probably give you better ideas, especially for prose.) At first you will find it a shock, but you will get a big buzz when you realise how much you get from reading the original (even haltingly) that is lost in a translation. Latin literature in translation often has a wooden or leaden quality, like a warm bottle of coke that has been left open for a few hours. You will see what the fuss is about when you get your teeth into the original.