Hello!

About  PHP version: If you have Dolphin on the same server or sub-folder, then it would be better to set php version 5.5.10 or 5.6.x Both these versions are compatible with Dolphin and UNA, but 7.x.x works only for UNA. 

About other settings: The simplest way is to sent UNA requirements to your hosting and ask them to fix the server settings according them https://github.com/unaio/una/wiki/Requirements