I would recomend that you don't pick your own for your first trip. Just worrying and thinking "did I get the right ones" in itself could give you a bad trip. First learn how to trip, then learn how to properly ID mushrooms. They are legal in the UK so go buy some, or get them online.
Don't mind any of them...If you want todo them...do them...if not don't...all I know is that I've done them a couple times before and they've never done me any harm...I've had excelents trips and no regrets whatsoever....shrooms are amazing...it's an unforgettable experience...they are different than other drugs...real different....I reccomend them...
Don't be scared, educate Yourself Wales, eh? I would advise You to hunt for Liberty Caps then (Latin name - Psilocybe semilanceata). These are one of the easiest to identify for newbies besides it is the very season NOW in the UK. I suggest You to do some research before going on a hike through manured grasslands. Shroomery and Erowid are the best places to start. Check out this link - http://www.shroomery.org/forums/sho...&Number=2644234 Also get a good guide. I would recommend Paul Stamets' "Psilocybin Mushrooms of the World" - the best book yet on the topic. Wishing courage and luck, me