Using Halo weapon models

More n00b questions. You all been real helpful in my quest to get my kid using Garry’s Mod.

He downloaded some Halo weapons model packs, extracted them to the addons folder like it said, but he doesn’t know how to pick them up and use them. How would he go about this?

They are just models. You can use them in posing and pictures, but you cannot pick them up and fire them.