my 01 pathfinder has 138k miles, showing code P0301, runs rough at idle. I'm thinking it may be #1 ignition coil, but the engine blows serious white/blue smoke when first started in the morning or after sitting a few hours. #1 plug looks a bit wet/black. Any thoughts?

First change your spark plugs and the change your oil and filter.
Have your truck scanned at auto zone to find code the check engine light is
on most likely from your truck running to rich or lean.
You might want to also add some restore to your next oil change it really helps. hopes this helps given the limited info to work with.