Don't know how you created the LiveUSB. I recommend using Rufus. I did burn the .iso using the .iso-method, NOT the dd-method (so everything as Rufus would suggest). The key problem for me was always, not beeing able to boot into the LiveUSB at all. One thing did the trick for me and I do recommend to try that one.
- Go into your BIOS and turn off "secure boot"
- Restart your laptop + choose your USB stick as boot media
Turning off secure boot helped me at least.