What equipment do i need to start a fitness center and equipment?

You need a place, a space you usually have to rent or buy.
You need showers, toilets, sinks, lockers.
You need treadmills, stair-steppers, weight sets, weight machines.
You need a counter and a cash register. You need carpet and mirrors. A sauna, hot tub and pool are nice. You need chairs and a scale for people to weight themselves. Raquetball courts are common. a running track is nice. basketball courts are good