try to focus on hub first, like add npcs, zombie slayer, wolf slayer, coal mines ect.
/warps you can easily visit any island without the hassle of installing the end or hub island every time you want to join. you can make it have multiple worlds within a single server,
revamp the /item command, make the armor sets and tools organized horizontally instead of vertically or seperate them to each command for example /tools /armor /items(blocks) /weapons ect.
Suggestions: