People at work...not what they expected????

So this has been bothering me...the other day while i was at work this older couple came in....(The women was kinda annoying) and i helped them out with there new laptop and questions they had. The women kept telling me oh this was a sup rise, you come across differently, your not what i expected. She was telling me i was very helpfull and she had other friends she would recommend me to for computer problems blah blah. So i was wondering how i can change myself a little to be more inviting toward people because im not an ******** type of guy. I guess i just dont know how to show my true colors you know. I mean i do get stressed sometimes because im working two jobs and its ruff. I just dont want anyone to think im an ********. How can i do that???