You need to follow the quickstart guide again - if you follow it to the letter, as long as the network works, it will work fine.
I expect you missed something important, like creating/starting a communication server?
Don't create your install set from one machine. Create it from the machine group. This will allow you to use one install set for multiple machines. When you run the installer on the client, our software will detect its machine name and put that in the database for you. This prevents you from having to manually create machine names in the database.
Download the new ePolicy Orchestrator (ePO) Support Center Extension which simplifies ePO management and provides support resources directly in the console. Learn more about ePO Support Center