Commercial Restaurant Space - Where do I start?!

[Kara Beckmann]

I have been wanting to get into commercial real estate this year and I have come by what could be a great commercial deal, however I am realizing just how different commercial is from residential when it comes to running the numbers. 

Current building is 5,200 with 61 parking spaces. Current site plan attached uses the existing building and permitted construction drawings have raising the roof and a whole new facade with a drive thru. 

The seller is willing to do seller financing on the deal, however how will I be able to pay the seller during construction and if I can't place a tenant right away. 

The numbers alone are seeming hard to get exact figures on- future assumptions, fixed - paid expenses, projecting rent, cap rate, tenant improvements, etc.. 

I would love to bring a partner in on this deal who is more familiar with this industry, however I don't know the numbers to present to them. 

ANY ADVICE would be greatly appreciated!