Requirement 1: Domain already exist and to configure email server for creating emails
Only emails need to be created if the domain already exists. You need to check if the same domain purchased server has mail server option to generate emails. If not, we need to check for Gmail or Microsoft or any other great mail servers.
Requirement 2: Need to purchase the domain and to configure email server for creating emails
If you need to buy a domain and need to configure an email server to generate emails.
Domains need to be purchased from domain registrar servers like Godaddy and Hostinger.
Eg: If we choose servers like Hostinger, we have the option to buy domain and mail servers from one server itself. There is also an option to purchase a server to host websites if required.
Requirement 3: Need to purchase the domain, need to configure email server for creating emails, and to host website.
If you need to buy domain server, mail server to generate emails and hosting server to host websites.
Ex: Hostinger Server provides all these facilities and there are others.
If you are thinking of using WordPress website, because there are free themes. A free theme can be installed and a basic website can be set up in a cost effective manner.