Part-time job

Evere since I was born, I have never earned money on my own.
I am given little money from my parent once in a month. I was able to live with it until high school, because I was alway doing my tennis club and didn't have time to spend it.
But when it comes to university, its different. We don't have school uniform so the pretty clothes are necessary, and in Tokyo, there are many yummy restaurants and cafes ( Which is very expensive.)

I had never experienced running out of money before so I have never done part-time jobs.
But I`m running out of money for the first time in my life! I got to start working as soon as possible.
I want to make full use of my English skill, so i am thinking of working at English clam school. But since I lived in America and use English without thinking any grammar, I can't teach children a  grammar.
Do you guys have any recommendation of working place?
If you do, please let me know!