I want to make a PBR texture pack but don't know how to start.
What programs do you use or anything.
Please help me! :)

That’s a long a complicated process ^^
I personnaly only use Gimp, but that’s because I do all the textures, including normals, by hand.
A program like substance painter could be a good way to start.

Here you have a wiki for the labPBR format, which is becoming the new resourcepack standard :
https://github.com/rre36/lab-pbr/wiki