After you feel like you're pretty casual with hiragana and katakana, reading and writing, you can go to the next step which is practice. Honestly, practice is the magical word when it comes to learning any language, I've experienced that many times. Try reading children books, join only Japanese forums/games, watching Japanese TV, basically anything you can think of and just practice until you're dreaming in Japanese.
Don't expect it to go fast. I've been learning the language for a couple of years and I'm not even near being fluent. Don't forget it's a very other type of language as we're used to. There is just such a big gap between Latin/Germanic/English languages and languages spoken in East-Asia.