General rule of thumb is practice practice practice.
Performing on your own and performing in front of a live audience are two different things. In front of an audience, your adrenaline will go through the roof which will mess with your timing. So that's why it's important to be able to do this really well up to the point of being able to do this blindfolded (not literally, but you get my point).
Also practice in the cosplay. Doing the skit in regular cloths and the cosplay is also different as you never know what will happen to the costume. You never know if you might have a wardrobe malfunction. So it's best to troubleshoot all this stuff before hand to know that your cosplay can handle the stresses it'll go through.
Practice your stunts vigorously. If there are things like flips, rolls, or falls, this will need a lot of practice.
Are there any other worries or concerns?
And I hope this helped.
When in doubt, just take the next small step.
With that next step take a deep breath. It calms the mind.
When the mind is calm you realize the best is still yet to come.