:wq command not found
It looks like there exists a line :wq in one of your shell’s profile files, such as ~/.bash_profile, which was probably added as a failed attempt at quitting Vim when editing such a file. 

To edit the bash profile with TextEdit, run open -e ~/.bash_profile in Terminal. Edit the file to remove the :wq line only. Save it, quit TextEdit and restart Terminal to see changes. You might want to make a copy of the file in case you're worried: cp ~/.bash_profile ~/.bash_profile.bak.

If you don’t want to use Terminal at all, see this answer How to add the PATH for mysql bin on Mac? with instructions on how to edit a profile file only using GUI.