When you buy a server on hosthorde does it run like any other server?

Yes, but not as an exact copy if that's what you're looking for. HostHorde provides you the server, while you have to set it up yourself. This includes permissions, plugins(public or custom), configurations, etc.
Mineplex runs on a proxy network system, which you can setup yourself with multiple server plans, if you want. Mineplex also has custom plugins which aren't open to the public, so some gamemodes/types may not be accessed without custom plugin development.

 

What do you mean by "like mineplex?" If you're looking for an exacy copy of mineplex, you'll have to create it yourself. Hosting services like HostHorde only provide the hosting, not the server content. Other providers aren't any different in this way, they won't be creating the server for you. If you want an exact copy of Mineplex, you'll need custom plugins as well as a lot of configuration to become similar. It's possible, but not practical. Basically, you at this level you shouldn't be trying to copy a server so large, or even copy a server at all. Successful servers come from originality, not from copying one that's already successful.

If you're talking about it being able to host a server at that size, no, any game server provider or shared host won't be able to handle thousands of players at a time. You can stull create a server network if you want, just purchase another plan for the proxy and link them together with BungeeCord/LillyPad.

 

Hosthorde don't help you create content. To run a BungeeCord Server network read this Guide: https://www.hosthorde.com/forums/resources/does-hordehorde-support-bungeecord-servers.26/