I Can't Edit My Model Normally

Q :Why are the points/edges/etc I select on my model colored orange/red/yellow, and why does moving them affect more of my model than I want them to?

A: You turned on Soft Selection [most likely by hitting the "b" key] Hitting the "b" key again will turn it off, or you can take the long route and open the tool settings and toggle it there.

NOTE: this mode can be activated and used within the UV Texture Editor as well.