1) Execution of your tasks:
stay in the outlined task, respect the deadline, give your point of view only if it adds value, don't talk in negative way bringing out only problems on execution without a solution.
2) Behaviour in your working team:
don't complaining about collegues but explain or suggest how it is possible to interact with them keeping a professional approach, don't tell on them!
always tell the truth especially if you made a mistake, in this way your boss can become your defender and ally, but above all he can give you solutions, training and vision.