Welcome to OFPEC!
Check out the Command Reference
page where all of the commands for BI titles are located. We have not gotten around to adding the Arma3 commands yet but all commands from prior titles are carried forward to each new title so you should not have a problem. You'll be looking for the Createunit or Createvehicle commands, as well as commands for removing/adding gear such as removeallweapons, removeallmagazines, addmagazine, addweapon, additem, removeitem, unassignitem, and a few other useful commands that you will be happy to learn of. For Arma3 commands, you can check this link
out and we'll have those commands up asap.
We're here to help you learn how to edit these titles, and learning the commands (or at least where to find them) is essential to expanding what can be done by basic editor features through the F menu. If you hit a road block or can't figure something out, try the search feature of the forums, we have over a decade of knowledge archived here that still applies to current titles. If you can't find what you need or don't know the keyword to search for, make a post and folks will step in, as life permits, to help you out.
Key words to look up would be create units, create groups, adding gear, removing gear, etc.
Happy editing bm!