[How do I delete the "world" file from my server]

/del world (worldname) 

 

 

[Does giving yourself OP disable advancements?]

No it doesn't disable acheivements

[OP]

3 hours ago, Henloingness said:

how do give myself op on my server

appearance > server commands > type: /op (gametag)

[HELP HOW I UNBAN MYSELF FROM MY OWN SERVER]

Server dashboard > Edit server > appearance > server command > Send /pardon (username)

 

[Can u delete a minehut server? Permanently]

you can also just reset the server that you want to delete and change the ip!

[Can't Use Uploaded World]

if your world doesn't pop up maybe try to upload it again!
/ul world (name) (file.io link)
/worlds to see al your worlds

[SkDragon not working]

If you mean player particles i recommend using the Playerparticles plugin 
otherwise try to repair the files or reset the config of the plugin!