Tags are a great way of labelling the git pushes as you progress through the development of your code.
You need to follow these steps
Create a git repo as normal
Make changes to the code base
git add .
git commit -m <message>
git tag -a <tag id> -m <message relating to the tag>
git push origin <tag id>
git push origin master
Lines 6 and 7 can be swapped.
Use the following convention for <tag id> vX.Y e.g. v1.4
As an example here is a git tag command - git tag -a v1.4 -m “some message”