Are you unsure about the level of your Git skills? Or did you start using Git recently and would like some pointers on where to go next? I hope I will be able to help you in both cases.
It’s going to be subjective
I don’t know of any metrics that you can use to assess one’s level of any version control system, therefore this article will be heavily subjective. If you know everything I mention in this article then in my personal opinion you can claim you know Git on at least intermediate level. If you aim at higher level of understanding Git then I would suggest you eventually go through Git source code and hopefully contribute to the development.
This article assumes you have at least basic understanding of Git, if you are just starting with Git then please consider covering the basics first. It also assumes you are working with Git console (IDEs do not count!). Without further due let’s get to the fun parts!