Zorin OS is based on Ubuntu, so it should be very user friendly.
It will also be a joy to update, as when Linux updates it updates all of the installed programs you installed through the OS repositories. Which means almost everything. I find it crazy to keep everything updated with Windows, having to go program by program. In Linux it is one simple command and everything is up to date again.
Zorin OS uses considerable RAM. Minimum is 8 GB. The Ultimate is 20 GB. Check what you have now. The good thing is RAM is relatively cheap and you can max out the RAM. Check to be sure but it looks like you have 4 slots that can use up to 32 GB of RAM. An 8 GB stick will be about $32. It's the single best thing you can do to improve performance.
The other two good things you can do are to install Linux as you planned and to install a SSD if you don't already have one. Those are screaming fast, use less power, and are absolutely silent. You could buy one when you soup up your RAM.