Whenever it rains my ac unit ontop of my house leaks in my bedroom. So I went up there an poured water into the ac, where the fan is located because that is the only place water can get in, the water I poured in started leaking but it was coming from in between the plywood and the sheet metal that the ac sits on. What should I do? Do they sale something that keeps water from going insite the fan area like a metal cover or could I build like a little roof over my ac unit?

That doesn't solve the apparent roofing issue you have. Have a roofer flash out the plywood to metal connection and use roofing tar to seal the roof. Even with a cover or "little roof ", windblown rain will still get in.