You don't need a devboard to learn AI, as long as you have access to a PC. Any decent graphic card in a PC would beat a small devboard any time no matter how well that devboard is praised by marketing fluffy words.
Any small board or USB accelerator for AI is just a toy when compared to an ordinary desktop or laptop. Small hardware AI accelerators are good for very low power devices, but hardware AI accelerators have no magic dust, they are just doing matrix algebra. Any PC can do better, and the most advanced AI/ML (Artificial Intelligence / Machine Learning) software for PC is free, open source, and usually works on any OS, while software devboard support will be dropped in a couple of years at most.
AI can sometimes help, but usually AI is unreliable and dumb. They have all the pitfalls we humans have: training a neural network is time/computationaly expensive, and inference (applying what it learned) is prone to mistakes. The only advantage is that once you trained a NN (Neural Network) on a powerful machine, then the inference is usually very cheap, for example a modest 100MHz single core microcontroller can do live face recognition from a webcam.
Training is expensive, inference is cheap. Then, there are many NN typologies, each type with its own range of applications.
- If you just want an AI based email spam filter, then just google about that, there is plenty of it already.
- If you just want to learn AI in general, then search for AI/ML tutorials that are not tied to a specific hardware product.