If the firmware is already installed properly and you have a properly FAT formatted SD card installed, setting up a new device is pretty straightforward. If this new device is not going to be a cluster root, but rather is going to be added to an existing cluster, really the only important details are the device alias you choose, and whether you set a device password. You cannot change the device alias once it’s configured, unless you factory reset (or wipe the SD card).
If this is going to be the root of a cluster, then the remaining settings are also quite important, (cluster name/frequencies) because once they are set for a cluster, they cannot be changed, short of deleting and creating a new cluster (and re-onboarding devices).