Well, even though I have no experience of Latin in a classroom whatsoever, I have found while learning other languages that studying it on your own is far more enjoyable, as you have no pressure to perform in an exam - you can go through whatever material you like at whatever pace you are comfortable with. Latin grammar is difficult - far more difficult than that of French or German, I find, and so you'll need a lot more time to get used to it. There are lots of free resources on here for Latin - download one of the free grammars and start having a look at your own pace. Alternately, you can look into a textbook. A lot of people on here use Wheelock, which is unfortunately something of which I have absolutely no experience whatsoever. The traditional methods might be better for you if you struggle with grammar, as they will probably teach you the grammar in a far more thorough way than the method I use - Ørberg's Lingua Latina - www.pullins.com
- It's a series of texts which teach Latin from nothing, using nothing but Latin, pictures and margin annotations. I don't know what you'd think of it, but it's well worth a look. Failing that, read a little about Wheelock in its own lounge, and if you're still not sure, ask questions!
Fortuna tecum sit.