Hopefully, you have assembled your team based on who the people are, not necessarily the companies that employ them. Spend plenty of time up front establishing relationships. When problems arise, you can usually work through them more easily. Pay attention to the budget and establish it at the beginning. Inexperienced administrators may not understand how expensive food service is.
Contingency funds are very necessary.
Don't be afraid to add that extra 10 percent into the budget, because you probably will need it. Watch out for fees. You don't want to be surprised by soft costs and design fees. I would be direct with your supervisors and administration. Tell them that you are excited and want to be a part of the project and budgeting process, but advise that it's crucial to invest time and money to bring in professionals for guidance.