It doesn't quite work like that.
You join up, post an introduction saying where you are and what you are about, then post a few reports of what you have previously done. Or, if you haven't done any, get out there and do a few and post them up. People get to see that you are serious about it then and may then be happy to share information with you.
First post asking for information when nobody knows you (you could be anybody - security to an axe killer and anything in between) usually does not get a good response for obvious reasons as it isn't an information bureau, it is all about give and take.
To get started, try typing 'Bristol' or 'Cardiff' into the forum search engine and see what it throws up. Even Google has been known to work too !
Good luck.