MY firebase data download qouta full .need help for New database platform for my app

Dear kodular. I have quiz app which is now have 20K download and 700 active user. But problem my firebase free plan data base download qouta is full .so I decided that I have to change user database platform firebase to MYSQL but problem is I don’t know anything about MySQL or SQLite Database .Please Help Me some who know this database setup .I can pay You. Or any one suggest me which database is Good for user database
My have app
Leaderboard Option,

If you can pay why not stay with firebase. Hosting an mysql database also costs money.

I have to give 25$ monthly .For only 20 gb download. And now my app data consume daily 2 gb.i want to purchase hosting for my data base

If you want only get and store data then you can use tinywebdb.