The alternative of Docker depends on on what you are trying to accomplish:-
If you want to run multiple containers on a single host, then you must use Docker-compose.
In case if you are trying to run multiple containers, but have them spread across a bunch of different machines, all of which are running the Docker engine, then Docker Swarm is the tool that does that.
But a genuine alternative of Docker is Kubernetes.
Or, if you are looking to marshal a bunch of Docker instances on an Amazon platform, you could look at Amazon ECS.
If you want to learn Docker then I would suggest you must take up the following Docker training course, through this course you can learn some other technologies such as Jenkins, Git and many more.I am also mentioning a video tutorial which you must watch to clear all your concepts regarding Docker.