I have not yet managed to achieve outdoor bouldering, but here's the little I know:

You need a crash pad, and probably a spotter. If you are going in a group, you may be able to share a crash pad with other people.

There are usually regional guidebooks about bouldering in particular areas.

Climbing walls often serve as a base of operations for people planning outdoor bouldering trips; if you go to a wall regularly you may be able to ask around and find out if people there are planning an excursion and if you can tag along.