About nerves...as a new performer you WILL have these nerves, you can`t get around it withouth experience, and the only way to gain experience is trough performing.
the only way to reduce the time it takes for them to dissapear is by beliving in your own skill, try to figure out exactly WHAT makes you nervous like:
are you afraid of messing up? (don`t be, everyone fails at some point, when you DO fail learn a lesson from it and you will turn that failure into a learning experience which in turm makes you better) if they catch you out, ask them what they saw and you can work on that part
are you afraid your effects aren`t going to impress/surprise/etc etc? Don`t be, the only way to truly understand how good your effects are is by performing and seeing your audience.
and final tip (actually 2 tips):
don`t keep your arms tucked in close to your own body,keep your arms forward and out, not reaching...but as if you are giving them something.
This unconciously signals openness both to yourself AND your audience
Watch your audience, not your own hands, this will give you invaluable information like when they are looking at something else allowing you to do your moves, it also signals you belive in your own skill...and once you have a few good tricks, it is VERY satisfying seeing the looks on their faces when you do something their minds just can`t process.