Hey!
You can do this, but keep in mind if you're hacking/cheating on another server, server owners may not appreciate it and they're welcome to ban you whenever they want.
As for a private server, remember to set the server as unlisted on your server dashboard, then turn on a whitelist (and add your friends!) if you don't want anyone else joining.
If you have any other questions, feel free to ask here or our community support forum: https://forums.minehut.com/forum/11-help/
Our discord is also a pretty cool place