So first let me clear a thing, a docker image is sort of a blueprint that will be used to create a container. It cannot run by itself, you will have to use $ docker run command to start a container based on it.
But first list down all the docker images you have using this command
docker images
then once you find your image copy its name or id and use it in the below command
docker run [options] --name [ name of the container ] [name of the image ]
example Here :
$ docker images
REPOSITORY TAG ID CREATED SIZE
ubuntu 12.04 8dbd9e392a96 4 months ago 131.5 MB (virtual 131.5 MB)
starting the container :
$ docker run -it -p 80:80 --name ubuntucontainer ubuntu:12.04
Hope this helps
Also If you want to become more adept with docker you can check this Docker training course . You will be trained by industry professionals who have years of experience in docker. Or you can refer to the docker tutorial for beginners blog.