You'll need texture WADs, which you can find here
Most WADs have a preview image.
These cover the original game:
Custom maps use a ton of wads, but these are very common:
Load these via the texture tab in the sidebar, it's at the bottom of the pane.
If you want to edit WADs so you can modify textures you'll need Wally.
Find it here, alongside other useful Quake modding tools:
Textures are embedded into the compiled map, no need to package any of this with your map.
Personally I have one big folder with all my Quake development stuff so I can link things relative to eachother inside of it. That way links don't break when you move stuff someplace else.
Forgot One Thing
If you don't see models, that probably means you'll still need to point Trenchbroom to your game directory. It's the directory that contains your Id1 folder. Scout the settings.
Also Read The Manual
It should cover these things.
I Should Porbably Try Ternch Borm One Of These Days
Does It Work With Burl Tumd?
I gotta say, I found myself accidentally thinking "TrenchBloom" quite a bit for a while when I started. It just... rolls off the brain.
Also, really, just RTFM. It's pretty good. Also make sure you're using TB2, not the older TB1 which appears at the top of the download page last I checked.
hi guys. i didn't find my textures in the program. I'm new here. i can print screen if you need help
Just drop the extracted wad files into a folder somewhere, go to the Face panel in TrenchBroom, and click the little "+" at the bottom to add texture wads to the map file. You should really read the TrenchBroom documentation before you start mapping.