I don't know how to "tag" my function in my data pack. Right now I use the function command in repeating command blocks, but how would I tag it so I don't need them?
You have to create the tag in the data pack, just like you created the function. The path is:
That file has to have a content like this:
<name> of course reference your function.
You can add more functions by appending
This will by default not overwrite ticked functions of other datapacks (but you could, if you wanted to).