Don't bother changing your grammar. It honestly makes no difference at all, if people judge you on how you type in a game, that's pretty stupid. People can read:
"hi there guys im new to blokland"
just a much as
"Hi there guys! I am new to Blockland!"
meaning there is no need to change your grammar, it's a game.
Act the way you want and you will have a lot more fun than listening to all these "how not to be stupid" lessons. You learn by experience.