I'm having problems, when I try to create a Database by Visual Studio this message appears:
As the error message itself says: you need to have LocalDB or SQL Server Express installed and running on the local machine, ie on your machine. I believe you do not have the program (s) installed and / or running.
To solve the problem, do as the message instructs, go to the link provided in the error message, select Microsoft SQL Server Data Tools, and install the latest version.