All of the listed tools are completely free to use!
For making data packs:
Software:
  -Visual Studio Code (to edit .mcfunction and .json files)
  -WinRAR (to zip and unzip files)
Websites:
  -Data Pack Generators by Misode (to generate loot tables/predicates/advancements and so on)
  -Minecraft Tools (mostly to generate json text components)
  -Minecraft Wiki (to get all the information and statistics of Minecraft)
  -The Minecraft Commands Discord (a lot of useful resources are shared here and people can help with any related problem)

  - The (even better) Datapack Hub Discord (a great community and the best discord for receiving help with data packs)
  -MCStacker (to generate complex commands)

Other Software:
  -Paint.net (to create all my art)
  -Hitfilm Express (to create videos)
  -Audacity (to edit sounds)
  -NVIDIA ShadowPlay (to record gameplay)