the crafting station that made the item also repairs it. Exception are the couple of items you can make without any station: those use the workbench to repair (a basic club for example).
its a little icon on the center of the left side of the interface to the crafting station.

your first crafting station is the workbench. There are other (?5? or so) crafting stations total that come along later.
you need 10 wood and a crafting hammer (build without anything, from a rock and a stick or two?) to make it. The bench needs a roof and walls around it so it isn't 'exposed' to function completely, but its existence will let you do the roof/walls basic building things. Once it has a roof, you can repair your club / axe/ craft hammer/etc.

What's a repair station? You wan't to repair what with it?
There is nothing that goes with this name in Valheim.
You repair your wood/leather gear in workbench, metal gear in the forge

Screenshot showing Repair button almost center of screen
Workbench repairs tools/weapons made at workbench
Forge repairs tools/weapons made at Forge
https://steamcommunity.com/sharedfiles/filedetails/?id=2915973134

In addition to having a sheltered crafting station, it also needs to be leveled up to make repairs of higher tier gear possible. I only remember the details for the forge, you need to upgrade it to level 3 or 4 to be able to fix every weapon and tool that can be made on forge.

See thats the thing, it said repair station, but its the other crafting thing the purple glowing one. Took me a bit but I got it through a creative world I have