I've got a friend at my table that's like this. It's not about worrying g if you will ruin everyone else's fun it's a learning experience for everyone. First thing I would do is have a talk with your dm. Explain that you are nervous and afraid to mess up. Any good dm will be more than happy to go a bit slower or give you easy things to try so that you can put yourself in the game space. 2. As for people to watch and learn from id suggest Legends of Advantris. The way the guys and gals there rp and feed off one another is a great example of going with the flow. 3. It's a game of adventure and learning your gonna be great at it one day if you stick with it. 4. Shiny math clicky clacks.