That's a 2 stroke. If you can find a serial number on it you can find a serial number decoder here which will help you determine the exact year:
https://www.vintagegolfcartparts.com...erence-library
Just going by the pic, that looks to be an early 90s cart. 91 - 94 or so.
Your cart can use any 2 cycle oil. That smaller tank next to the gas tank will hold the oil. A note.......
Those carts came with automatic oil systems that mixed oil and gas on demand as the cart was being driven. That system wasn't designed well and a lot of people disconnected it and just mixed gas / oil outside of the cart like you do with a weed wacker or something.
Look to see if if all of the oil lines going to and from your oil are still connected to your engine. If so, the original system is still in place. If not, then your cart has been converted to "manual mix" and you should mix your oil and gas at 85 to 1.