Microsoft® SQL Server® 2012 Service Pack 2 (SP2) Express

As you said in comments you’d like a SQL Server + a SSMS.
I would suggest not using a SQL2012, but going for a more recent version.

Using this this link you can download the SQL Server itself.
The 2 free versions are express and Developer. More information about the differences between versions can be found here : SQL Editions and SQL Pricing

• Developer you should use if you’re just trying to develop some things at home, NOT COMMERCIALLY. It has all the features enterprise has.
• Express will give you a basic sql server with some limitations.

Afterwards you can get SSMS using this link.
SSMS is free, and its just used to work on your SQL Server