In any organization, two things are guaranteed: change and challenges. Change will come daily in the little things, and regularly in the big things. Change may come without warning, or it may be purposefully enacted. Either way, you must be prepared to deal with it.
Challenges will also come in various forms. You may be required to solve budgetary issues, equipment failures, or unattainable deadlines. You will also face challenges with people. Unreasonable expectations, lack of planning, or personality conflicts. But how you respond to people will speak more to your character than theirs.
Working with people can be fun, and a bit of a tight rope walk, but you must remain honest, candid, and open. Don't bad-mouth a fellow team member or speak ill of them in any way. If you complain to someone else who only agrees with you but doesn't have power to enact change, you are gossiping. When there is a legitimate issue, work through the proper channels, try to resolve it with the person directly, and avoid gossip at all costs.