Models not appearing in my server.

Hey, I am in the progress of making a server. It is a custom rp, and I added some weapons, but they only appear as a red box in the corner. When I add weapons to my server, am I supposed to put them in a folder for downloading or anything?

You likely need to install cstrike content. There is some info on the wiki about doing so here:

If you rent from a hosting company, you will likely have to ask them.