As others have said, you're not going to get paid much. Just my opinion but I think the best part is that you're going to be learning Japanese as you translate.
To start actually translating VNs for companies, you'd want a history of translations to show off your work. These can be anything as long as they show interest. The majority of people probably don't have anything to show. There are many paths to start. Manga translation groups always seem to be looking for translators. E-h always has translator requests up. Fan translations also for VNs.
You don't necessarily need to know Japanese (if you're just translating text/images), but you should probably know enough such that google + a few J-J dictionaries is enough to understand 95% of sentences. The good thing is actually translating stuff will teach you Japanese and smooths out your rough edges. Ideally though, you should probably already understand like 25-75% of sentences without a dictionary before you start translating.
To get to that point, you need to learn Japanese enough to actually start and that's where most people get stuck/stop as learning Japanese from 0 takes a long time. There are many paths to do this. If you're an absolute beginner, I hear refold is the best way to learn any language the fastest. Suck at talking? Talk to real people (I'd like to know where to do this). Suck at kanji? I grinded anki decks (wnkn+knjdmg), although immersing + mining is likely better as it probably won't burn you out. Can't understand sentences even knowing all the words? I'd suggest watching a few cure dolly videos as I had the same problem and it was because the English school system of teaching Japanese is broken (imo as someone who learned JP in high school). Heck, since you're in this subreddit, re-reading your favorite VNs in Japanese is also a good option.
Once you've learned enough JP to be considered fluent and demonstrated a good understanding of English through your translations, I'm guessing most companies would want you. All of the above was pulled out of my ass but seems like it'd work to me.