Help with making a swep

I recently finished a gun model I made using Blender, and exported it as a .smd file using a plugin and compiled it into the .mdl, .phy, .vvd, etc files for the game. I also have a custom .wav sound and the .vtf and .vmt texture files for it. And I have the shared.lua file.

When I get in game, it’s in the weapons menu, but when I click on it the gun is a big ERROR sign that I’m holding, I guess, but when I shoot it’s my custom sound.

How would I go about fixing this to show my gun model instead of the ERROR, or if anyone has any links to good tutorials for this, that’d be helpful as well.

Thanks.