If you’re not currently strength training (get on it!), get a solid 4-6 weeks of training under your belt before adding power exercises.
Training power requires a lot of speed and coordination. Having a bit of base strength will help you control those movements.
If you’ve got knee pain or such, it’s probably best to avoid jumping for now. Yet another reason why kettlebell swings are such a good option.
Whatever the power exercise you’re doing, get the form right first. Increase the speed as you become more confident with the movement.