SSH port open to the world: safe?

Hello there. I am fairly new to self hosting stuff (currently an SMB share ...) but I'd like to know whether it can be okay to have an SSH port open to the world? I'd sometimes like to demonstrate stuff, maybe turn on an apache2 server, or just play with my environment when I'm on the train for example. My server runs Debian 13.

Not port 22 obviously. Was thinking of setting up some 5 digit port number (which I would configure my router to forward). But what about the security? Do I need to care about bots that regularly run through the IPv4 address pool and try nasty things? Is a regular 10 character password + the high port number safe enough? What are your thoughts, how are you solving this? And how can I monitor break-in attempts?