Core workouts are any workout that really torches your abs, obliques, back and lower body (as your quads are your biggest muscle and connected to the pelvic floor).

So even just simple sit-ups help. Kettlebell swings are a great all-around, but I think one of the most effective are squats. Squats are a full lower AND core workout and a great one to throw in engaging the pelvic floor on.

On any exercise that causes your core to engage you engage your pelvic floor on the OUT breath - which is the exertion - i.e., a squat is hardest coming up from the squat, so you engage at the bottom of the squat and disengage at the top, where it's easiest. I found squats to be extremely effective at tiring my pelvic floor out to the point I couldn't even engage it anymore after doing those for a while.

If you can add weights, that's better. But, I'm just giving guidance, you should talk to a personal trainer with pelvic floor certifications or a pelvic floor therapist - your level of fitness now might dictate the type of exercises they prefer that you do - plus the fact that if you're already incontinent may impact how they want you to work your pelvic floor in addition to kegels.