You may wish to install a sample database from Microsoft called Adventure Works 2014. The reason you may want to do this is because a lot of books and videos use this as an example. They often show queries from this database as examples and it helps to have it installed so you can follow along more closely. Also, you may just want to have a look for yourself. So, how do you install it? You need to download it, unzip it into the Backup folder, restore it, check that it installed correctly and check your permission to it.
The installation page is at Codeplex. Choose the recommended download, which is the full one, and the one at the top of the list of links.
For a website of instructions, you can look here.
There are lots of videos on YouTube. For a YouTube video you could try here. It’s not necessarily the best one, it is just the first one I clicked at YouTube. However you don’t need to worry about the script. At least I didn’t have to. I’m using SQL Server 2014 Express Edition with the SQL Server Management Studio (SSMS) 2016 version. You can run a query from SSMS to get your version:
I followed the instructions at the website mentioned above and had no troubles. You can follow along with Microsoft’s instructions on how to restore a database here.