Your going to want strength training and lots of it, so low reps I'd stick around the 6 reps mark as a maximum.
Lots of compound lifts (squats, deads, bench, rows, pullups) and lots of core work is important.
I'm kinda on the fence of you needing to do endurance work since 1 your still kinda new to climbing and 3, your climbing regularly (although regularly could be once a week) and they alone will work on the endurance.
So for getting your workouts right, full body 3 times a week, all strength training and do cardio.
Always stretch after your workout, especially since you mentioned you need to become more flexible, yoga is great for flexibility and core stability if you find an instructor who is good with working the core.
Above all though you want to keep it simple, as simple as possible, compound lifts, the only thing I'd recommend focusing on is your grip strength because your going to really need it and that will be the major contributing factor to your climbs.
The guy above me posted the 5x5, it's not a bad workout to look at if you want a simple full body workout.