I need an architect

I am in search of an architect to assist with commercial plans to renovate an old building into a sandwich shop. Currently the building has two stories however, the owner is planning on removing the top floor. The owner has requested us to submit drawings showing our plans to do a build out of the building. Once this is approved we will be able to lease the building. The property is C2. This is all very new to me, and I'm not sure how to proceed from here.