So I'm just getting into riding and am doing about 15 miles rides (today was my longest at 23miles.) I had a tune up a month ago, but I have no idea how/when to clean it. I've watching videos on youtube about cleaning the chain, etc, but how many miles can I ride before doing so?

Can you please tell me the easiest way to clean it and how often it needs to be done? I don't have a trainer or anything to hold the bike down while cleaning the chain either.

Thanks!