You cannot host a site on production, without a valid AEM license. It will have legal issues with Adobe. Please reach out to Adobe to get a license on behalf of your website and then you can host it.
Once you have the AEM product license you should be able host any number of websites on production. Now when it comes to websites hosting globally, you will need to choose a domain for your website, for which you will need to buy a SSL cert and you will need to register the domain with any domain provider.
If you are going to host the website on AEM, you will need at least one AEM Author Instance, one AEM Publish Instance and one dispatcher followed by Load balancer and CDN for better content caching and delivery based on the global edge location. Again these specifications will varry based on the nature and number of websites and the amount of end users/traffic that you are going to get on your website.
Yes, definitely you will need the deployment tool which can be Jenkins for automated deployment process of code.
If you are using EC2 instance, you will need to setup the AEM instances on the EC2 machine first. You might need multiple EC2 instance for hosting multiple AEM instances like I mentioned above. Once you have the AEM instances available you will need to establish connection in between them, i.e. Author -> Publish -> Dispatcher -> Load Balancer -> CDN -> DNS
This has so many steps to follow to setup an instance and host the website on AEM. Please follow the below links and you will have some idea about the AEM website hosting: