Cannot run named container

I’m new to Docker, I have pulled some images down and have two containers. I’m trying to run a command inside one of the containers I named MyContainer. I’m getting the error message shown in picture. I logged into the image as well.

Names are case sensitive. It took me longer than I’d like to admit for me to realize this.

I had tried that as well, but the main issue was that I did not understand the difference between executing commands on a running container vs. starting a container the exec for commands. The container MyContainer in this case was created from the image already.

Container is down.
You must use:
docker start MyContainer
docker exec -it MyContainer powershell