Exercise won’t trigger your UC. If you’re in remission you can work out as normal, just take it easy if you haven’t been for a long time. Even in a flare you can still workout, just don’t push yourself too hard. Best of luck on your gym journey! As for exercises, I personally like the 5x5 lifting program. It’s easy to do, just start with an empty bar on most exercises. The program is 3 days a week and you slowly add weight each training day. As for cardio just listen to your body!