Good camping area easily accessible by Dublin public transport?

I am brand new to camping outdoors, have only stayed in a tent at festivals and in my friends back garden! I want to give it a go this Summer for a night or 2, in the Dublin Mountains/Wicklow area? Anybody know of a suitable location which is accessible by public transport (neither I or the person I plan on going with have a car) and maybe plus a bit of walking (I wouldn't have any problem walking 5-10 km if I knew where I was going). Not too familiar with the Geography of Wicklow, I know you're not allowed camp anywhere near Glendalough, and that there are certain rules that have to be obeyed if camping in Wicklow National Park. Anyone know any nice safe place (which is still secluded) that I can get to without too much hassle? Thanks.