>>2815290 (OP)
>>Am I way too late to be planning something like this? I’d either go in late September or early October.
No. You're actually looking at an ideal situation. Flights booked too early or too late usually get more expensive. 2-4 months is a 'goldilocks' zone. Flight, room, cash. That's really all you need to plan. For the rest it's more fun to just wing it.
>>Are there any places worth visiting that aren’t completely flooded with third worlders? We have plenty in America.
It's the same as in America. The capitals are very cosmopolitan/international. So if you want a real native experience aim for the 3rd, 4th, 5th, etc. biggest cities to avoid tourist and browns. But it obviously depends on your destination, just google demographic data of the place you're eye balling.
As a last recommendation I'd aim for a 2 week trip if possible. I just returned from my first international trip to Europe from the US and I only booked for a week thinking it'd be enough. But that week included travel days to-and-fro, so realistically it felt more like a 4-5 day trip. Or to be more precise, jet lack is a bitch, and the first day at your destination you'll probably just wanna spend the day recovering, and the last day packing your shit and preparing for departure, so take this into consideration. Safe travels. I had a blast, already planning my next one.