@yookonii sorry mate, can't help there. I heavily relied on Froid_san in acquiring all the texts. All I did was normal translation. But if you're serious about it, you can check the VitaPiracy Reddit and ask for help.
When it comes to tutorials on JP>EN translation, what I recommend is that you at least know very basic Japanese. Like even N5 level could be sufficient, but it will give you a hard time. I didn't use any translation software, so I don't know what to recommend. However, the VN you want to translate is based off the anime, so you can just watch the anime and compare it to the game, which will help speed up dialogue translation.
But honestly, I don't recommend you try to translate it, besides being the same as the anime, it's still a 20 hour game. To put in retrospect, it took us a year to translate a ~10 hour beat em up.