Answer 1

you can use sqlite for practice as it is not heavy and it is for small databases

http://zetcode.com/csharp/sqlite/

Answer 2

Try sql express. It free.

With sqlconnection and sql command.

Or

Have a look at entity framework.

MariaDB is also a good database. That can connect with sql.

https://www.sololearn.com/Discuss/2518660/?ref=app

Answer 3

Which IDE do you use?