Read this: https://ctf101.org/cryptography/what-is-xor/
25% of the time you see an XOR challenge in a CTF, you will have been given multiple XORd messages. Based off of how XOR works, you can XOR them against eachother and do something called a crib drag. I recommend this repo for crib dragging, but there are also online solvers.
Do this crib drag problem. https://medium.com/hackstreetboys/securinets-ctf-quals-2019-useless-admin-crypto-4e2685452fec
The other 74.99% of the time you see an XOR problem in a CTF, you can solve it with something named xortool. There are also websites online that do the same thing, but will fail on larger texts.
Complete these two writeups:
If it doesn't get solved with xortool, you're probably just doing it wrong, because the magic math should work. Also, resist the urge to bruteforce with xortool... if that happens, you're also probably doing it wrong.
Submit a sentence or two on what you had to do to solve these challenges and anything you struggled with understanding.