If you have knowledge of Linux terminal, you can get a Google VPS and host your server there. If you have web hosting knowledge, you can even get an actual panel instead of just using commands; Pterodactyl's a great one. Google's going to be your safest bet for hosting. As for server exploits, plugins often have bugs; I believe there is currently a bug going around involving a plugin (the one to link multiple servers, can't remember the name) that allows to get Admin commands. The wiki and the forums (spigot forums or whatever you'll use) will be your best help.