Whilst you can use an basic camera that has rtsp, you gain a lot more functionality if you buy certain brands.
The best place to read to learn the difference is here, which since this was last updated Reolink API has been added.
If you want to be able to move the PTZ camera you will need to choose a camera that has working and correctly implemented ONVIF functions. Not all cameras that advertise ONVIF will actually move via correctly formed ONVIF and some will only move when 1 of the 4 different ONVIF methods are sent.
A quick google on the camera to see if people are moving the camera or at least that brand in ONVIF software not just openhab is a good idea to check with. The two brands @JimT should be a good choice, with Hikvision you need to create and enable a ONVIF user before it will work.