Please tell me you plan to use ssh keys and preferable fail2ban and a firewall on your machine if you are not using a VPN / Cloudflare tunnel.
https://www.tomshardware.com/how-to/use-a-secure-key-for-ssh is one starting point but u/flaming_m0e nailedit - what actually is your problem?
I would also ask - what do you aim to do?
Some clue as to your network kit (esp the router and if you are on CGNAT) would also help.
Domain does not equal email…
You also need an email server and they should tell you how to set up the MX records for your domain. As you are using Namecheap, you will find it easy to use their email service at https://www.namecheap.com/hosting/email/
Using Outlook as the mail server for your domain is possible BUT it depends on your MS contract and some, e.g. 365 Personal have changes coming up at the end of this month - start at https://support.microsoft.com/en-us/office/get-a-personalized-email-address-in-microsoft-365-75416a58-b225-4c02-8c07-8979403b427b
You used to be able to use Outlook on the web to pull from SMTP or IMAP servers so you had everything in one inbox but I honestly do not know if that exists now and still requires the external email server.
Have a look at Cloudflare tunnels.
Easiest way would be to run it on the server (either Docker or direct command line) and this will give you http / https / ssh access to the server with an option for different types of authentication.
There is a walkthrough https://www.crosstalksolutions.com/cloudflare-tunnel-easy-setup/ - a bit out of date for screen shots (Cloudflare change the screens frequently it seems to me) but lots exist on the net / YouTube if you get stuck.