Lets see how i can assist you with this. Will need the questions answered.
Your revenue is coming two ways:
Set monthly rental fees
Percentage fee based on their income
Do you know how many may fall under each category?
Are you only accepting tenants that have existing practices?
The way the space is configured how many can operate at one time?
Are they individual offices?
What is the capacity of the center as in space hours available etc?
For operating costs
Estimate your utility use
cost to do marketing for your clients