Teleporters:
http://www.interlopers.net/tutorials/1828
Glass that you can shoot through (and I'm guessing is not passable):
Make a func_brush brush entity, texture it with a glass texture, set its collisions to Never Solid, then make a new brush with the TOOLS/Playerclip texture over it.
Buttons:
Make a nodraw textured brush if you want it to be invisible, textured if you do, make it a func_button, go into the outputs then type
Onpressed
Target Entity***
Output***
And like Dr Forrester said, these are things that dont belong in a tf2 map, but if you just want to learn the ins and outs of hammer, by all means do so. Just please dont release it. Maps that utilize teleports/buttons/shoot-through glass are usually super gimmicky and not fun.
However like I said to learn its alright, and if you need any clarification on anything feel free to ask.