Can a non-university student live in shared university housing?

Hi all, I am 18, just finished school, and I am going to start Royal Marines Officer training next September. This means I have an entire year out where I can train and get some life experience. I spend a lot of time trail running and mountaineering, I saw a part time climbing job opportunity in Snowdonia / Eryri and thought it would be a great opportunity to spend time away from home, get very mountain fit and also enjoy a different part of the country. looking to spend a few months there. However, I will have to rent property. Since I am so young I don't have a credit score etc and may find it difficult to justify the costs of some property. From searching around this seems to be the case. Nonetheless shared student housing seems very budget friendly for me. However I am not sure of the legalities of this, would I be allowed to stay with university students whilst myself is not studying at university? Btw, the closest university is Bangor if that helps with specifics.