If you're a noob one of the most important thing is community support/documentation/help. And it seems like Beagleboards has sorta slowly died/gone in the dark (awaiting for the new RiscV one) (this is entirely my own opinion on the beagleboard community, and may not be accurate!) Some of the most documented hardware is Raspberry Pi. I know Microchip has some tutorial-based MCU and MPU's for sale.
As for the wireless BBB, there is no difference, just added WiFi and Bluetooth (http://octavosystems.com/octavo_products/osd335x/), if you don't need those get the BBB (REV C), there are different revisions of it. The green one is from (seeedstudio) and it has the Grove connectors or whatnot, check into whether you want those or not.
There are great books for the Beaglebone (https://www.amazon.com/Exploring-BeagleBone-Techniques-Building-Embedded/dp/1119533163/ref=mp_s_a_1_1?crid=34QPQSOFXZ5IV&keywords=beaglebone+black+book&qid=1640627072&sprefix=beaglebone+black+book%2Caps%2C322&sr=8-1).
If you buy the BBB (Rev C) and that book, it's a decent starting point IMO, you should be fine and good to go.
Someone lemme know, but I don't think you can even buy BBB from adafruit or seeedstudio anymore; as they have ran out of stock a while ago
It may be better (or at least much cheaper) to simply buy these books:
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Exploring BeagleBone: Tools and Techniques for Building with Embedded Linux
Exploring Raspberry Pi: Interfacing to the Real World with Embedded Linux
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