every time I start my terminal, it always says "-bash: .: command not found" twice. Does anyone know how I can get rid of that?
It sounds like you have an errant command in a file like .bashrc or .profile. Try opening those files and looking for a command that doesn't belong. If something look suspect you might want to copy and paste it into Terminal to see if it runs correctly.
You might also check your prompt if you've customized it to see if you introduced an error there.