Yep. You need to come out with some people who know what the hazards are and will keep an eye on you so you don't make any serious rookie mistakes.
There are many ways to get in a serious pickle on a rope and many ways of getting in a pickle in a mine when you have successfully completed your ropework.
You would be surprised about the lack of air in Gwennap and Scorrier mines. Some of them are dangerous.
SRT is one of those things where your granny could do a 100m shaft on kit that is set up properly and you couldn't do 10m on kit which isn't set up properly. I remember my first outing in a 60ft shaft. My lengths were too short and I pretty much pulled myself out by my arms....if you've got some gymnastics to do at the top of the shaft, you need all the energy and help you can get.
You don't need to join the rescue team and learn industrial HSE approved multi colour coded rope and which hand to hold what with, but you do need to know how to set your kit up and use it properly and have someone who can be by you when you screw up and work you through your mess.
I have been stuck at the top of a 240ft shaft with knackered arms because I rigged it wrong and couldn't get out. Thankfully, I was pulled out of the cage by my feet. If I was alone, it would have been on the news.
There is nothing like getting in a bloody mess on a rope.