Hello, good afternoon, I come to ask you why I want to create as a VPS to offer other users

I have a friend who offers vps through containers, he told me not to use virtual machines, because they spend a lot more, so I come to ask you some questions that I have.
First, how do I get people to join the container via SSH? Another question, can I limit the use of ram, processor and allocate a disk space? because my idea is that several people use different resources.
I also want to know how I do so that they are not all with the same IP, so what should I do, assign a different port to each one or what do I do? And how do I assign a different port to each user?
Last question, how do I manage the containers? or is it not necessary to manage them and the console is enough for me?