Minecraft create your own texture pack?

I sometimes see on TikTok how people pixel swords from Minecraft or something else

I wanted to try that too and wanted to ask how it works

Is there a website for that or something?

if someone knows, please contact us

You only need 3 things:

A drawing program e.g. Gimp
An idea what you want to do
time

Then you can download the https://texture-packs.com/de/resourcepack-de/default-pack/ and change it as you want.