In reply to Marky78:
There's not really any special "training" required, just some different things to think about that you don't have to deal with indoors.
E.g. making sure your mat's actually in the right place so it's underneath you at the crux (hint: this is not necessarily where you want it at the start of the problem), learning to read the rock when it doesn't have the holds nicely marked in bright colours, spotting people, deciding what you don't want to risk doing without a spotter if you're climbing on your own, etc..
If your local wall offers some sort of "indoor to out" day and you'd prefer to get a bit of guidance (especially as you're pretty new to bouldering) as you venture outside, you could go for that.
Or find some more experienced boulderers and tag along with them -- that'd be ideal.
But it's also possible to get a mat, a guidebook and get on with it. That's what I ended up doing.
There are various places like Burbage South valley boulders where you can play around pretty safely on your own on many things with one mat and no spotter, with lots of stuff at gentle grades.
(Burbage South is also handily about 15 minutes walk from the bus stop or car park. And the pub.)
Just drop any expectations about what grade you "should" be able to climb -- indoor grades don't translate very well, especially when you're just getting started outdoors. Start on the easiest things possible and see how it goes