Hi Wayne, first of all, welcome aboard from my side as well!
To answer your question: if you want to have a costume approved by the 501st, no weapons are needed. For some costumes, you have higher costume reference levels that require weapons and also some necessary greeblies/attachments on them (e. g. the E-11 blaster for Level 2 and 3 approval of the Stormtrooper). Concerning the blaster themselves - you can 3d print (pretty much all of them with the right files), you can get resin casts of some (DC-17 clone sidearms, E-11), or you can buy a toy blaster, sand them, paint them and add some stuff. It's all up to you, really. I personally liked the idea of having some weight in my hand, so went for a resin E-11 build which looks awesome and is certainly heavier than a 3d print, but after some time trooping, it does wear out your arms quite a bit. So for my next costume, (a clone commander), I decided to just go for 3d prints for all his guns.
Look at the builds, look at the files, do some test prints, and most importantly, if you have any questions, HIT US! ;)
Best wishes from Germany,