I kind of want to learn Japanese. I want to be able to watch untranslated anime and understand what they are saying.

One of my flatmate takes weekend classes as he's a full time web dev.
You can do the same. 😎

It takes a while, but it's very interesting. If you just want to understand grammar and vocabulary, you can probably get away with only basic reading knowledge. It feels alien at first but the grammar is generally straightforward. Vocabulary takes a long time though.
読んだり書いたりしたいなら、大変だけどね。２０００時間ぐらいかかるかも。

Learner here;
what do you want to learn specifically? as in: just understanding unsubbed anime or also have conversations with natives?
depending on what you want to learn, that determines what you should learn in the first place (things like: kana, kanji, pitch accent, etc)

@Trithon the chance of me actually having a conversation is pretty slim. The shows often have kanji in them. So I should probably learn to listen and read a bit.