Being in Katy, you're kinda in between the two main groups of disc golfers in Houston. In the cypress/spring/woodlands areas you have the Northside Chain Gang who runs a weekly rotating mini on Saturdays and on at Spring Valley on Sundays(that has two $500 ace pots right now).
IN the Southside you have Birdshot/Gorilla/and EricJ and Co. in Sugar Land that all sort of team up for events and minis on the south and southeast parts of town. I'm in Cypress so I'm not as familiar with them, although I have played their events and I have nothing put good things to say. In the spring/summer there is a rotating handicapped mini that EricJ runs.
As for leagues, the only one I know of is at Agnes Moffit. I think they're 2 or 3 weeks into the current Saturday league. And I believe this is the last league they're doing until the time changes. Once DST hits, there's a 6 week, Thursday only, flex start league 5-630 at moffit.
As JRW said above, Facebook is really the best outlet for info on DG in Houston. I would join all the FB groups listed above.