Use underground rated, UV resistant 12-2 with ground wire. Make sure all outllets are GFI protected.
Run the wire along the top beams to keep hidden. Fan must be outdoor rated. Lights and outlets should also be outdoor rated. Main wiring feed should be sized by an
electrician. Make sure amp load for lights, heater (if electric), exhaust fans, pumps, air conditioning, etc. are included in the wire sizing / panel specification. Length of run also
needs to be factored into the calculation.