What DBMS to choose?

Question

Android

Good time everyone. Need help choosing a database. I want to create an android application in which the client will sign up for a service. I was prompted by firebase, but when working with it, there was a problem filling it out, since there will be many fields (date, name, number, mail, time) and I need the lists to be connected to each other. For example, by date, display the entire list of recorded clients or, by request, for a date to display free time. Please tell me what is better to work with or leave the choice on firebase?