Currently in the same boat, though I’m a citizen

1. Figure out your car and drivers license stuff. Some countries let you swap one for the other.

2. Mail forwarding. Either forward your mail to someone you trust or pay for an international forwarding service. You’re still gonna be getting mail afterwards, like credit card renewals.

3. You’ll likely have to do the same for finances

4. Go through everything you own and trim down. Whatever you don’t get rid of, you’ll have to deal with customs.