You are only as strong as your team.
Everyone must know their roles and responsibilities. Also, you must know everyone else’s roles and responsibilities. Knowing what the other members roles allows you to help them even more. The easier it is for other people the easier it will be for you. If you do not know everyone else’s roles just ask. Do not be scared to ask questions. There is no personal success or failure. If you fail then the whole team fails.
The goal is bigger than you so always do whats best for the team and project!