My cousin disappeared sept or oct not sure which but we have very little to go on. Not sure how to find out if he used a uhaul or other company to move his stuff. Or how can we find out if someone went out of country like tracking a passport or plane tickets?

You go talk to all the neighbors who lived in that area and ask them what type of truck they saw.

The other records, will require a court order, so there has to be a open civil case where this is needed for evidence.

But talk to all of his friends, and see if they know anything