Answer to Question 1
A professional appearance conveys that you are confident and responsible and that you respect those around you. People will take you more seriously.
Answer to Question 2
Accepting extra work without complaint shows that you have positive work habits, a positive attitude, and a good work ethic. Missing out on the social function could ultimately be a small price to pay for the opportunity to demonstrate your willingness to work hard and to build a positive relationship with a supervisor who can help you succeed in the workplace.
