Be re-assured that providing you ensure that you have working fastboot & ADB installed upon PC, it is almost impossible to "brick" such Android device; that said it is always more difficult being a late adopter as too many referred to links become "404"with passage of time. Usually all that is needed is to place .zip upon root of SDCard for it to be visible from recovery, although suggest TWRP be installed earlier rather than later.

Whilst Amazon is your preferred choice here is one which would just need your Jolla account to go and I'm sure other users would vouch for condition of my device(s) offered on forum previously.