easy question
 

Is there an undo button or command that I can use in case i have made a mistake and want to go back to my previous version?

Re: easy question
 

I propose :

File / Resume model.

(If you have saved your model before...)

Re: easy question
 

RECOVER could be helpful

Re: easy question
 

VUNDO will undo any changes made to vertices only. Otherwise you have to use either resume or recover.

Re: easy question
 

Directly not, probably all mentioned above. Resume model alvays works, but you need to save model after each performed command.