'Since my topic below starts with phrases like 'that's probably your first...' 'Oil change' in the style of 'I'm too stupid' (the oil should be warm

), it was closed, and now I have to fix it.
I've changed so much oil that I've lost count, but only on Corasas and motorcycles, never on a brand new car!
Therefore, I would rather inquire about potential faux pas.
I just did that. The only annoying part was having to screw the lower engine cover back on afterwards.
The oil drain plug didn't have a crush washer, but I got one from the rental workshop.
I also replaced the two O-rings on the oil filter cover, but I'm not sure what the purpose of the lower (smaller) one is!
By the way, the oil filter could be easily turned by hand, and it fit perfectly with the oil filter wrench! (@Jan)
I held it firmly and turned it a little further with the oil filter wrench.
It was full at 4.5 liters.
I found the passage again in the manual

. It states: other engines, 4.5l diesel: 5l.
funny?
I haven't found any oil standards. Could someone perhaps find the relevant one for me and explain which one it is?
I paid: 5 liters of 5W40 oil: €17, oil filter set: €6.5, sealing ring: free

, rental workshop: €13.5 (1 hour).
And it's NOT my car!
The oil is definitely not as black as it would be after an oil change on a Seat, but it's still somewhat yellow. It's not as light as it would be with a gasoline engine, but you can tell that it was a proper oil change.
So, that had to be said.
Thank you.