I need information…

Hello dear community, I would like to change the engine and transmission oils from my 5,7L (350cui) and the THM350 and would like to know the approximate filling quantities so that I don’t order unnecessarily a lot of oil. And which oils would you recommend to me? Motor oil = 10W-40? Gear oil = ATF3? Haven’t changed oils on my Camaro yet, how do I change gear oil? Where do I leave off and where do I fill up again? How can I get to the filter? pecial procedure? And still ne gaaananz stupid question: I can’t find a filling nozzle for filling the engine oil… Could someone please give me a quick guide on the correct working method? Thank you…