I left for Australia 12 years ago. I was gone 6 years. I remember wishing I had set up, before I left:
1) a way to send and receive texts on my USA number. Why? to get confirmation codes from banks, craigslist, and other accounts.
2) set up USA versions of streaming media (music, videos). Region-locking means never being sure you can see what you want when
3) a good forwarding mailing address. I had used a UPS post office box, but it was expensive and didn't actually forward my mail overseas reliably,despite the nice clerk saying they would. (this time I'm trying travelingmailbox.com, not sure how reliable they are, but hopeful)
4) renew driver's license.
5) "lose" your old and replace, or apply for new, credit cards, to get LONG expiration dates. ALso make sure htey have 24/7 live support, We have Capital One, and they let me confirm "it's not fraud, it's just me traveling" by email! nice.
6) craigslist. I still use this relic for housing, and back then, they were VERY fussy about overseas logins. I assume it's only gotten worse. I remember being locked out, could not post overseas, without my old USA phone (which I had screwed up and let my number lapse) Make sure you have an account with all the USA based verification they'll let you have.