Be in charge of your own enjoyment. Pick the right games to play in by reading the whole blurb, not just looking at the titles.
Introduce yourself to the GM and the other players before the game starts.
Be present during the game. Put the distractions away. Make eye contact. Be ready when your turn comes.
Select a character you’re interested in playing. Ask the GM for clarification on any details you don’t understand and ask to change any aspects of that character you are uninterested or uncomfortable in portraying.
Get involved in the story. Find or make reasons for your character to interact with the other players and the GM. Give them something to work with in crafting their own portrayals.
Share the spotlight. Do heroic things with, and not to the exclusion of, the other players.
You don’t have to be a master of the rules and mechanics to fully contribute to the game. Describe what you want to attempt and let the GM help you make and interpret the correct rolls.
Buy into the story. Note the mood, setting, and genre. Cracking out of character jokes might be fine in a pulp game but can easily ruin a horror game. Don’t derail a planned adventure without trying to work within the framework first; most convention games won’t be as free form or sandbox as a home game.
Interact in character. Speak, strategize and negotiate with the other players and the NPCs as your character not just as a player.
Use those Bennies! They allow you to try more difficult maneuvers, do multiple actions and take risks. But don’t be afraid to fail, sometimes these are the most memorable and fun part of the story.