Ideally you are working with a managed server and often times they can install it. In some cases its no charge.
Otherwise the actual installation is fairly easy provided you follow the instructions explicitly. You can find those for a linux server at...
https://github.com/boonex/dolphin.pro/wiki/ChatPlus-Installation-Instructions-%28CentOS-with-Apache%29
If looking at that page looks like you're reading an alien language you may want to consider taking advantage of the beta cloud server Rocket.chat is offering. It's totally free while in beta and they install the entire chat server on their servers. It takes a couple minutes and is available instantly after that. And they've added the dolphin oauth so you can use it with your dolphin site.
Go to https://rocket.chat/deploy to set this up.
Good luck