Don't wait for someone to magically give you the ability to make maps. Google for hammer editor tutorials. I remember there was a website or wiki or sth that tought me everything I needed to know to get started.

This will help, but it won't do the work for you: ABS TF2 Mapping Pack

Well I don't know what you want specifically, but I can list some stuff that I would have really loved to know when I started. First things first, though, locate hammer in your TF2 directory: It should be in "common/Team Fortress 2/bin", as hammer.exe and hammer.bat. You'll probably want to run hammer.bat first.

1) TF2 maps are made up of two things, basically speaking: Brushes, which are pieces of geometry made specifically for the map; and entities, which are logical things built into the engine where it decides what they mean.

2) Brushes are *convex* pieces of geometry. This is part of how map compiling necessarily works. What this means is that there are no "insets" on a brush, and if there are, then it's not a valid brush.

3) Brushes aren't collections of vertices, they're collections of flat faces, and if any of those faces are made non-flat, then the brush will either totally break or it will look different after saving and reloading the map.

4) Anywhere on a map that can have entities needs to be totally surrounded by solid brushes. What actually this means is that you can't be able to draw lines from any entity on the map to the void outside of the map, ever -- that's called a "leak". This is a necessary part of how maps are compiled, again. Also, "solid" means that a brush doesn't have any transparent textures, and isn't a "displacement", and isn't part of a "brush entity". More on that in tutorials and stuff.

5) An extremely basic basic TF2 map looks something like this:
https://dl.dropboxusercontent.com/u/1811521/basic_tf2_map.vmf

http://i.imgur.com/vFJW8Pe.png

It's not something I would play on for very long, but it has everything that a map needs to compile and run correctly. I'll go through a list quickly.

- Entities are surrounded by solid brushes, with no "leaks" to the void
Skybox brushes, which the skybox is rendered behind ingame, "seal" the map as solid brushes.
- Map is lit -- has light sources
The light_environment entity on the ground is a special entity that almost every map in TF2 has. It defines the way which sunlight and sky light comes out of skyboxes onto the map.
- Has player spawns
Needless to say, the engine doesn't like it if you don't place spawn points.

I also included some brushes with the tool texture "player clip" on them. These are special brushes that things like projectiles and bullets can pass through, but not players. These are used all the time in TF2 to "clip" things. That is to say, make invisible walls. People put them on roofs where they don't want people jumping, and walls where people could get stuck on props or other details easily if they weren't there.

If you want to go somewhere from here, read some tutorials on tf2maps.net. They probably have the best tutorials for people looking to make TF2 maps specifically, though some of them haven't been updated in a while! Maybe that would be a good project for me...