SSH and port forwarding. New user

Not sure if this is the right place for this. I recently switched all my writing workflow to the terminal in vim and I love it (Humanities major, no true coding experience at all). What I want to be able to do is access my store of plain text files and notes that exists on my desktop computer at home when out and about. This may be from my laptop, my phone, or work and school computers. I managed to figure out how to ssh into my desktop on my home network which felt like a big win. I set up port forwarding such that I can access my desktop by typing "MYUSERNAME(not root)@WANADDRESS -p HIGHRANDOM PORT NUMBER" but I have heard that leaving a port open to the internet like this may result in my desktop getting compromised.

On my laptop I set up a key so I can just type "ssh homecomputer" and it automatically logs me in with my username and the correct high port which gets forwarded, but I fear this may not be possible on work or school computers.

Is it safe to have the port open like this? Does the lack of a regular username help me in this regard? Anything else I need to know to be able to access my desktop from a variety of devices through ssh?

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