If you are not doing a few years learning plumbing and getting at the basic an NVQ3, before you get on the gas, you are going to have a bad time my friend.
You will realise on the first job that you know nothing about plumbing and heating, you won't even be allowed on site as you will be...
To be fair, i don't see anyone using anything but Paslode guns on site. It used to be air compressor city on a second fix, with sprayers to roofers using the air.
Really quiet sites are these days, it is stupid that i miss that.