I have just brought a MK3 fiesta with a 1.6 engine swap. It has a few issues i will list.

Heat does not work = suspected heater core as foot well is slightly damp. How do i connect a new heater core to the 1.6 engine?

High Idle - Seems to idle a bit high.

Bit smokey on startup

Fuel smell inside the car.

How would i go about troubleshooting?