I suppose it has a lot to do with how extensive your learning materials are, or if you have a good teacher or tutor. You'll have to put much effort into it above and beyond your classroom study or homework.
I would recommend studying your grammar book religiously, and then start trying some composition. Writing Latin or any new language is more effective than reading for mastering the language.
I also recommend learning your vocabulary from English to Latin. In other words, dont look at the Latin word and try to give the definition in English. Look at the English and then give the word in Latin. That's a simple trick, but it worked quite well for me. It's also the ages old way of learning Latin vocabulary. It's harder, but it works better.
Another tip: when you come across any grammar point in your book, or anything else that you want to remember, write it down in a notebook in the form of a question. Then come back later and see if you can still answer the question. If not, go back and look at it in your book until you get it. Same way with vocab. Study the vocab it until you can just rattle it off without hesitation.
That should get you quite far in a couple years, but I'm not sure if it would be far enough. I also dont understand why they want you to be fluent in an ancient language.
'Greek had to be simplified, and Latin had to be replaced with Italian, because we barbarians stole so many Greek and Latin words.'