What’s the pcv vent tube?? And how much in total do you think I’d be spending?
Heres the trick to be able to figure out answers to questions quickly:
For this example i'll use your initial question about oil on plug:
go to google, type in question you have, pretend to talk like a cave man for best results and then add "site:newcelica.org" to the end so you have something like this:
"spark plug oil site:newcelica.org"
This will return results from old posts here on the forums. You'll usually need to read through a few of the threads to find answers. Sometimes people will chime in with good info or leads to things you didn't even know you may need to do. I suggest reading through at least a few diff threads on a specific problem to see if it all lines up. Takes just a few minutes once you're used to doing this a couple times. The first result in this example gives great insight about things I wouldn't have been aware of when I was a new to this such as the valve cover gasket. Post #6 from Smaay shares some good info, but that was back in 2013, in 2021 the odds of your valve cover gasket being pliable are getting lower.
You can use that same method to find answers to what part numbers are for example google "Spark plug gasket part number site:newcelica.org" or "pcv valve replacement site:newcelica.org" and if you need number for that job it'd be "pcv valve gasket part number site:newcelica.org"
Im not telling you this because I think your questions are bad, im telling you this so you can find good info fast from all the old threads and make the hobby less frustrating as a person new to repairing/diagnosing the celica.
Theres another more reliable method of getting part numbers but this is already a wall of text, lemme know if interested.