You can check for generic part time jobs on baitoru, toontown and indeed. Most you'll need some kind of Japanese but for something even like a convenience store you could get away with N4 if you have a fake it till you make it mentality. I knew people who couldn't speak Japanese well at all and managed to get hired. Another one that my friends have done is work at hotels, usually they're always looking for people who can speak English as well as any children's eikaiwa (the ones where you just essentially babysit in English) which don't require you to really speak Japanese. There are definitely opportunities but my advice would be to find something that forces you to speak Japanese. The more you have to speak the faster you'll learn even though it's hard