You can't do that in Gmod Cinema without admin commands.

if i had admin commands how would i do that?

If you have ULX installed you can use the "ulx ent" command to create weapons if you know their entity names. If you don't have ULX installed, then you can do it by setting sv_cheats to 1, and then using other generic entity spawning commands to create guns. I don't know what those ones are though, so try searching them up online.