It seems double unders have been a limiting factor for alot of people. If you would like some help learning them, ask one of your coaches.
Monday Strength/Skill Work: Warm up to include jump rope practice. Single Leg OH Lunge (Bulgarian Split Lunge). This is done with one leg elevated behind you. Use a bench or box. 5 x 8 each leg. Alternate with weighted pull-ups/pull-ups. 5 x max reps.