SQL Server Licensing for training, small scale development
What I would do in your case is the following:


Download HyperV and install on your machine, details here: https://blogs.msdn.microsoft.com/virtual_pc_guy/2010/07/07/installing-windows-virtual-pc-on-windows-7-home-editions/
Download Windows Server 2016 evaluation edition here:
https://www.microsoft.com/en-us/evalcenter/evaluate-sql-server-2016
Set up a Virtual Machine using HyperV (this is a good skill to have anyway and is really easy to learn. Search online for a tutorial).
Install the Windows Server 2016 on the VM.
Download SQL Server 2016 developer edition.
Install Developer Edition on your new VM with Server 2016 and SQL Server 2016 and enjoy the benefits of the latest release of both products.


Remember afterwards that there is a bit of firewall configuration if you want to install SSMS on your local PC and connect to your SQL Server 2016 VM (also look this up on the web). SSMS is compatible with Windows 7 still, so you are OK to install locally and connect it to your SQL Server 2016 VM.

You may also require quite a bit of RAM etc for this approach. I had a 2011 laptop with 16GB of RAM and a SSD drive running 5 VMs on HyperV a while ago and it ran OK. Your mileage will be different depending on your PC specs.