I'm new to the pentesting scene and following a youtube tutorial for beginners. Of course the prerequisite is to have kali linux installed, so I'm trying to install it. I want to do a single-boot install, wiping away my previous os.

Hardware:
usb stick
Asus transformer book t100ta
Memory: 1.8 GiB
Processor: Intel Atom CPU Z3740 @ 1.33 GHz x 4
Graphics: Intel Bay Trail
Gnome: 3.28.2
OS type: 64-bit
Disk: 30.7 GB

Steps I've taken so far:

1) format usb with diskpart on a windows machine (clean > create partition primary > format fs=fat32)
2) downloaded Kali Linux 64-Bit (Installer) and used balenaEtcher to write it to the usb
3) plugged usb into my asus (running ubuntu 18.04.2 LTS currently)
4) turned asus on, pressed F2 to enter setup utility
5) added UEFI: General USB Flash Disk 1.00 as my Boot Option #1 > Save changes and exit
Result: boots straight into Ubuntu
6) turn off asus, turn it back on, pressed F2 to enter setup utility menu again
7) boot override with UEFI: General USB Flash Disk 1.00
Result: it flashes blue and goes back to that setup utility screen

What step am I missing?