You will need an email hosting service or host your own mail server (really not recommended). There is a free service called Zoho Mail, that's what I use. If you want more control and more options you can buy Microsoft 365 with Outlook which is 5-7$ per user, or Google Workspace which also costs about the same, or Zoho also offers more premium plans. For self hosting you would go with a Microsoft Exchange server but honestly it's extremely hard, and the server license is expensive. You need to have an actual physical server and stuff like that, so just use a service like the ones I mentioned above. That's about it. Good luck setting it up!
Edit : Zoho offers very good documentation and is extremely easy to setup. Just lookup Zoho Mail. For Microsoft 365 and Outlook you will have to use the M365 Admin Center and also configure stuff in Azure Active Directory, so quite a lot of stuff, so basically Microsoft 365 is quite more difficult to install for a non-technical user like you. I would suggest hiring someone to do it for you if you don't wanna go the easy route.
You will need an email hosting service or host your own mail server (really not recommended). There is a free service called Zoho Mail, that's what I use. If you want more control and more options you can buy Microsoft 365 with Outlook which is 5-7$ per user, or Google Workspace which also costs about the same, or Zoho also offers more premium plans. For self hosting you would go with a Microsoft Exchange server but honestly it's extremely hard, and the server license is expensive. You need to have an actual physical server and stuff like that, so just use a service like the ones I mentioned above. That's about it. Good luck setting it up!
Edit : Zoho offers very good documentation and is extremely easy to setup. Just lookup Zoho Mail. For Microsoft 365 and Outlook you will have to use the M365 Admin Center and also configure stuff in Azure Active Directory, so quite a lot of stuff, so basically Microsoft 365 is quite more difficult to install for a non-technical user like you. I would suggest hiring someone to do it for you if you don't wanna go the easy route.