How do I create the right architecture for a multiprocessor application?

I have a question about the architecture of a JEE application that is supposed to provide private spaces on the server (and database) for businesses that make an account with us.

Am I better off creating a new database for each business, or putting everything in one database?

I am currently using Spring Boot, Spring JPA Hibernate, Thymeleaf, MYSQL. (I also have android side to connect to my servlets)

Should I stick with these or is there something better?