Once you start opening the doors to the internet, there is no limit to the opportunities that exist. All it takes is a new idea. But this will get expensive if you have to rely on others to set up, host and promote the sites you think you want to run with. It will get expensive if you do not give yourself the room to make the mistakes you are inevitably going to make.
Before starting out you need to learn to drive. To take control of what you want to do and where you want to go. It doesn’t take long to start registering domains every time another great idea presents itself. But it gets painful if you are incurring hosting fees every time you do. Particularly given that most of them will never see the light of day.
The reason you have to choose an account that provides for the hosting of multiple domains.