Hi,
Better do more digging on how to create before popping the question, there are already many threads out there but you could have a look here:

You need to learn how to use assembly for sro_client.exe editing (Olly or x64dbg) and mysql for database edits. Eventually it would be a plus to know some basics for website programming (but for this you can also find website templates which require minimum website programming knowledge in order to get them functional).
Hope that answers you questions