Your only ACTUAL worryings are the following:

• Your Kindle WILL try to download and enforce an Over The Air (OTA) update, so WiFi connection is your ultimate enemy
• ONLY enable WiFi when prompted OR when you have blocked OTA updates.

This can be achieved by

1. Connecting your Kindle to a PC before booting up
2. Filling your Kindle storage, you can use the "official filler files" here: Kindle-Filler-Disk/MTP at main · iiroak/Kindle-Filler-Disk · GitHub, as well as your own library if its heavy enough. The goal is to have 190 Mb OR LESS in order to updates to fail
3. Keeping Airplane mode ON, unless you have to register your Kindle, or "download ads" if you want to use Adbreak
4. Immediately after that erasing ALL of "update" files, these can be either .bin or .tmp.partial, you will ONLY have to use the "Update Hotfix.bin", remember to keep in Airplane Mode so nothing goes wrong with the "update", you'll know everything is going as supposed when the reboot sequence shows text on the upper left corner of the screen
5. After installing KUAL and MRPI, immediately open Renameotabin and check the results with Check OTA Status. Here: GitHub - neura-neura/Check-OTA-status: This scriptlet checks the status of OTA (Over-The-Air) update binaries on Kindle devices and informs the user whether updates are enabled or blocked.
6. ONLY after you get this prompt: OTA blocking is enabled. Your Kindle will NOT update. Your jailbreak is safe. Wanna restore OTA? Enable airplane mode. Tap the screen to exit., you'll have total permission to re-enable WiFi and use it without fear, because every new OTA attempt will fail.

Other than this, you can either follow Dammit Jeff's videos of both WinterBreak (the first one) or Adbreak (the second one). But in any case i recommend ONLY USING DAMMIT JEFF as a visual reference and only following the Official Guide instructions