Newbie question on starting mining

Hi, I have been investing in coins and am now looking at a bit of newbie mining. I would like to see if GPU mining in a mining pool works first before investing in an ASIC machine, as I have a reasonably powerful gaming PC which I also use for work, so presumably while I’m working (Outlook/Word) and not using the GPU intensively it could mine? The idea being to save electric costs as I’ll have the machine online anyway all day. Does that sound sensible?

Otherwise I’m wondering if electric costs in the UK make ZCash mining worthwhile as we’re not the cheapest country for energy!