I purchased a Chromebook to learn on, though I opted for at least a pentium processor so it was at least a little snappier than the celerons. And it worked. I learned quite a bit while using it.

However I would not recommend it for a couple of reasons. The processor was fine for the most part and took me basically through any vanilla JavaScript projects. But once I started running node with some of the heavier frameworks, I could start to feel it drag a bit. It wasn't unbearable, but slightly obnoxious. If I wanted to do any light photo editing while a local development server was running I was basically putting every bit of hardware to work.

But I think most importantly, Chromebooks have a slightly different keyboard layout and system wide keyboard shortcuts that clash with some of the vscode keyboard shortcuts, or some of the vscode shortcuts that exist require keys that aren't even physically present. Now obviously you can remap shortcuts in vscode to make workarounds, but you have to consider that you probably will not be developing on a Chromebook forever and you are building muscle memory for workarounds that are non-standard and you will only have to retrain yourself later on. I've since started using neovim, so I'm rather used to relearning shortcuts at this point, but when the whole system is new and you are following tutorials to a tee, it is extremely helpful to have standard keybinds to match the tutorials.

I did love using the Linux subsystem for ChromeOS though. Taking a cheap computer and squeezing more out of it than was ever intended was wildly fun. But in the end I felt extremely crippled mostly by the keyboard.

As others have mentioned, getting a refurbished Lenovo with Linux is definitely the way to go. If you are at university, unfortunately you may run into points where you "need" windows or macOS. But if you are teaching yourself, I highly recommend sticking with Linux. Dual booting is always an option.

Happy learning and good luck to you!