It get’s better with experience. I have nuked my system countless times at the beginning.
If you are too frustrated with Linux maybe give it a rest or consider dual-booting instead. It sound that you are frustrated and don’t have a clear head to troubleshoot.
You have an old android so I don’t remember how it was.
Currently there is notification/popup to enable mass storage through USB.
KDE connect works through network so not really through USB. (Works through tethering USB tho)
Also check cable as they ware prone to breaking.