All right, I might sound like an idiot but... where is the Transmission dipstick for a 1994 RX7? My RX7 is manual transmission. Is there a dipstick or do I just fill it in a fill plug somewhere in the transmission till it's full? Basically, how do I figure out how much transmission fluid is in my manual transmission 1994 RX7?

Your RX7 does not have a dip stick. Instead, it has one check/refill plug and two drain plugs.

Manual Transmission Hex Head
Fill Plug 18-29 ft/lbs
Drain Plug 29-43 ft/lbs

Manual Transmission Square Head
Fill Plug 18-29 ft/lbs
Drain Plug 23-34 ft/lbs

Manual Transmission Capacity: 5.3 pints of SAE 80W-90 GL-5 Gear Lube

Rear Differential Capacity: 2.8 pints

Drain the transmission, after it reaches normal operating temperature. I'd refill with either Mobil 1 or Amsoil synthetic GL-5 gear lube.