Minecraft server at Zap-hosting install mods and plugins?

I've rented a server at Zap-hosting and now I want to pull plugins on it, mainly Worldedit and Worldguard, later more. I have already looked at many videos about it and just can't get it, maybe someone wants to help me in game. Maybe somebody can give me a tutorial especially for the Zap-hosting plugin. I have also seen in many videos that have a server folder, if you need it for how do I get it?
I'm happy about every answer, best regards

You go to their FTP server and load the .jar files into the plugins / folder.

Reboot / reload and good