Mercury 4 stroke questions

[Gary H NC]

Trying to look some parts up online without much luck.
Thought you Merc pros could help.

2002 90HP ELPT
Serial,OT-563433

Need a part number for the impeller kit,
What spark plugs?
How much oil the crank case holds and any other tips for the impeller change and changing the oil.

My first 4 stroke...

Thanks for any help.
If anyone knows of an online service manual that would be great!!