Hi Tracy, here's one tutorial: https://www.youtube.com/watch?v=T7mYB6x68DY
Go to you tube and watch the tutorials on that. Very helpful and will walk you thru the process.
there are some posts here on hometalk which may help https://www.hometalk.com/search/posts?filter=concrete%20work%20top
We have done a few. I love the way the look. https://www.alifeunfolding.com/blog-1/2019/5/28/how-to-diy-a-concrete-bar-top-in-a-weekend
Here is the other: https://www.hometalk.com/18147786/changing-up-an-orange-formica-countertop-with-concrete