Hi,
If I get a VPN how does it work?
Can I use it on my TV and pc at the same time?
Does it work on the router or just specific devices
I literally know nothing about them so excuse the stupid questions.
It depends on what VPN you’re using, but most VPNs can be used on multiple devices at once. It is possible to have your VPN work at the router level, so that all your traffic runs through it, but it’s more complicated for a less experienced user than just using one on your phone or streaming box. As far as how they work, the VPN will encrypt and route your traffic through one of their servers, which can often be in another country. This is what will allow you to, in some cases, watch geo-restricted content.
I’ll happily help you out with understanding vpns, but may I ask what you plan on using one for so I can possibly personalize my answer?
Thanks a million 
Geo-restricted is the word I couldn’t think of.
I’m not a total virgin at tech so how complicated is it to run through the router?
Watching stuff that isn’t available here. BBC iPlayer etc
Not too complicated. A lot of the services may even include step by step instructions on how to do it. Google search is a good resource for instructions as well