Answer 1

There are websites where you can design your database.
https://dbdesigner.net/

After designing yours, you can download SQL code of the database from the website (Export -> SQL in DBDesigner) and execute the SQL statement on various SQL Servers. (MySQL, MSSQL, OracleDB, PostgreSQL...)

After these steps, you need to deploy your Database to a Cloud Application Platform. (Heroku, AWS, Azure...) I would recommend Heroku but Heroku uses PostgreSQL natively. So you will need to change your MySQL to Postgre if you did MySQL at the first hand. You can do the change with:

https://devcenter.heroku.com/articles/cleardb