Round the World Fares

You could start by researching the "around the world" fares. Once you have some basic info on the cost, maybe create a spreadsheet or some kind of table that you could use to compare them. After that, start to narrow it down a bit (I think that Google will be your friend here, maybe with a bit of help from AI). There's a ton of info on the web about traveling around the world, so I would look at that first. Maybe try FlyerTalk.

I did find a few threads when I did a quick search on the forum, however.

https://community.ricksteves.com/travel-forum/general-europe/around-the-world-airline-tickets-any-thoughts
https://community.ricksteves.com/travel-forum/travel-partners/travelling-around-the-world-in-2024
https://community.ricksteves.com/travel-forum/trip-reports/around-the-world-in-80-days-85afeb3b-a795-4a3e-b75f-bf2368658561
https://community.ricksteves.com/travel-forum/transportation/around-the-world-plane-tickets
https://community.ricksteves.com/travel-forum/beyond-europe/your-recommendations-for-an-around-the-world-trip
https://community.ricksteves.com/travel-forum/general-europe/around-the-world-airline-tickets-any-thoughts

Thanks! I will check these out.

Just curious. Is this the great value it used to be? Years ago I occasionally met travelers who were doing round the world trips for about what I paid for a single return trip.

We used the Star Alliance (United) version years ago when I was based in Singapore in order to combine my business and leisure travel. Probably did it 10-12 times between my wife and I. It's a great deal if you have the time. The rules are pretty similar for the other alliances (One World and SkyTeam) as I recall, but best to do a deep dive into the individual alliance websites to familiarize yourselves with their specific terms and conditions and maybe do a comparison check, though the one associated with your home airline will be likely be most convenient and cost-effective.
One suggestion: though the rules state that you have to keep moving east or west on the RTW fare (ie no back-tracking or side trips) I found that by selectively using local regional airlines to supplement my RTW trips I was able to stretch things out and explore further afield without affecting my RTW itinerary.
Used to be that I only had to confirm the date of the first leg of my trip and was then able to plug in the dates for my other stops as the trip progressed, so the added flexibility was a big help for me. Not sure if that's still the case but might be worth checking out.
In my case the cost of the RTW ticket was less than a round trip fare from my home base in Singapore back to my company headquarters on the US East coast. Like I said - it's a great deal.