I have experience running a server on Ubuntu.
I'm in the opposite situation to you.
I ran the server using the L1J-EN Classis master package, but I cannot connect to it as a client. I will give you the advice you need.
you help me too.
Preparations for running Ubuntu,
1. Ubuntu operating system
2. Wine applications
3. Serverstart.sh (use not .bat file)
In my case, since I am Korean, I ran the Korean version of L1J. Since the Korean package uses euc-kr encoding, I experienced a headache with language encoding problems when running a server with Ubuntu. But if you speak English and you have an English operating system, you won't have any problems. UTF-8 encoding is a commonly used encoding, so I don't think there will be a big problem.