hey guys i was wondering if i could cycle my tank with no light and no heater or do i need them for the bb. thanks

You will be fine with no light and no heater!

x2 as long as you have no tropical fish, cold water fish will be ok or are you fishless cycling.

im not sure yet but i was wondering which way of cycling is cheaper?

fishless you buy some ammonia,( or pee in your tank a bit... )
With fish you'll have to buy some goldfish or small other fish and feed those a bit to get the ammonia you need .
I'd go for the goldfishcycle.
Goldfish are easy to rehome, once you have to take them out, when your oscar is going into the tank, when the cycle is up and running.

X2

Goldfish are the cheapest way to go

how many gold fish would you recomend buying for a 75 gallon for a cycle

I would start with 12 feeder goldfish. They are about 15 Cents each at any pet store in the US!

I would get enough goldfish so that they weigh at least twice as much as the oscar/s you are going to buy. You cant have too many goldfish but you can have too few. also feed them well when cycling