Just a few "silly" questions regarding Websites / Hostings, etc?

[Askto]

1.) I already bought a domain at GoDaddy.com, then I just realized they have this Auto Website Builder, which includes everything, Domain, Web-Builder, Hosting.. What can I do now, I had already bought a domain?

2.) Is the ratio of Website vs Hosting is 1:1 (one is to one), which means 1 Domain per 1 Hosting?

3.) Is domain & hosting also included and free (GoDaddy.com) for 1-month plan? Or only for the yearly plan?

4.) I really dont understand hosting, can I buy 1-hosting, then buy many domains, then run it on only 1-hosting?

Thanks for your patience in answering my inquiries..
Also, can I buy only email account? What then would be the domain after "@" (me@domain.com), do I need to buy it? If yes, do you think I must create a website for that domain, since knowing that I also need to pay for that, right?
@Duncan

3 Domains (1 Website for every Domain), so 3 Websites all in all

Is it possible to run all 3 domains under 1 Hosting only, at GoDaddy.com ?