Latin for Duolingo is the unofficial Latin course I've been writing here for a few years. Though it's not interactive, there are links to some Memrise courses that are. It will get you to an intermediate level and should help with what you're learning in school.
You might want to look into the textbook series Linua Latina per se illustrata by Hans Ørberg. It focuses on natural acquisition of the language and fluent reading instead of translating and lots of grammar.