As you say, you'll have no time at Raleigh. However, at Phase 2, there may be a club of some sort on the base and almost certainly in a town nearby.
Clubs come and go, as people in charge (the driving force) get drafted and the club declines and folds. I ran a successful karate club (based in Sultan, for many years) as luckily there were a few people capable of keeping it going.
At Phase2, see the PT staff and also look at the local area's web site.
Sumo used to do Judo - not as some think, Sumo wrestling...............