Program Ideas

Hello FP - just coming back to the site and started exercising at gym. Doing 30 mins on treadmill - 15 on Arc or eliptical - abs - some tricep extensions - but I'm at the gym for 1 1/2 . Just don't know how to put a routine together (Ex: Monday do ????? so many reps; Tuesday do ????? so many reps, etc.)

Ideas anyone ?