Hi Brian:
I feel the best way to meet other birders who pursue birds throughout the US is to go to birding festivals and go on as many field trips as possible. Introduce yourself to field trip participants who seem to be both serious about finding new/different birds, and are also willing conversationalists / informal instructors.
The Rio Grande Birding Festival in Texas in November was the largest or second largest festival in the nation. A key location! The Space Coast Birding & Wildlife Festival in Florida in January is usually either first or second in # of participants as well as in field trips, indoor lectures, vendors, etc. I worked for Rockjumper Worldwide Birding Adventures at each of these venues for 5-6 years, where I co-led field trips with local experts, learned a lot over the years, and enjoyed these times tremendously. There are many other festivals in the U.S. some really good, a number of others rather poor. Use Google a lot.
As far as foreign birding goes, much of Central and South America that you mentioned are great destinations - and sometimes nearly overwhelming - places for birding. I strongly recommend Rockjumper Worldwide Birding Tours (
https://www.rockjumperbirding.com/ ) and their long list of tours throughout the world. Pre-covid we offered approximately 300 tours each year to all continents and about 100 nations. Give them a look! And, good luck with this form of recreation.