Datapack doesn't work

Disclaimer: I have never created a datapack, have all of my information from random web pages and have probably done a stupid mistake.
My datapack doesn't work. The folders and files are in the picture. 
Here is the pack.mcmeta:
{
  "pack": {
    "pack_format": 71,
    "description": "Ampeln"
  }
}
The load.json:
{
  "values": [
    "ampel:main"
  ]
}
The tick.json:
{
  "values": [
    "ampel:ampel_tick"
  ]
}
As far as I know everything depends on those files. In the main.mcfunction I currently only have:
say Test
If you're wondering: Ampel means Traffic light in German.