Creating a sport club (or not?)

Hawkward

Hi everyone,

Let me explain quickly, I've been practicing a martial art for a few years in France and moved to Ireland for work. Now that I'm here, I'd like to give some lessons. At the moment I have a few colleagues I train with in parks but other people want to join, but in the case where someone is injured I guess that I am liable for that.
Thus my questions :
1. Can/should I make people sign a waiver of liability in my name for the practice of the martial art? Would this have any value without having a structure and be enough for an outside practice?
2. Should I create a structure? If yes, which kind? (Knowing that I don't ask for any money, we have a special kind of association in France for that (law on associations 1901, but here I don't know, non-profit organization?)
Any other advice is very welcome
Thank you!