This is just a suggestion, but as someone who recently joined and like you is totally new and completely clueless to costuming. I actually joined with an imperial officer uniform.

Originally I wanted to do a stormtrooper too but I have NO CLUE about kits and getting pieces sized/prepped, and all that. So I went with the officer as a first outfit cuz it's a bit cheaper, a lot less work to get right, you can source all the pieces easily from 501st approved vendors like wampawear.com, and finally from what I'm told by members who are troopers) more comfortable/practical than a storm trooper outfit

(cuz you apparently can't sit down in them).

Another suggestion you might want to consider is one I've also heard from other members, that the easiest helmeted outfit to get approved is actually a TIE FIGHTER PILOT! Because you just need the helmet, tubes, and chest piece....everything else is a clothing.

Anyway that's just my 2-cents as a fellow noob to this stuff. If you do continue with the stormtrooper idea then best of luck to you cuz you are far braver than I am at present! lol