I'll be flying from AC from YVR-HNL and connection on HA to KOA. These are separate tickets however I know AC will be able to check in my bags all the way to KOA, but:

1) Should I check-in online on HA prior to departing YVR.
2) If so, should I select that I have a checked bag even though it is coming from Air Canada? What about the bag fee?

Thanks for your help!