How do I add Counter-Strike (TTT) weapons to Half-Life 2 Base?

I have finally figured out how to use the Hammer Editor. I opened it up and started creating maps on the Half-Life 2 "Base". However, I am making the map for TTT for Garry's Mod, which I presume uses Counter-Strike weapons like the sniper and the shotgun. How do I get Counter-Strike weapons into the Half-Life 2 base map I am working on?

I do not own any Counter-Strike games.

Quite a simple answer... and silly I didn't find it in the first place.

With the ttt.fgd file installed, I got an entity and named it to weapon_zm_(Weapon type). This came up as an error in H.E, and while playing HL2 nothing showed up, but in Gmod it showed up and worked.

Here is the tutorial I got it from