Questions about VOCR

Hi
I am planning getting VOCR but I have some questions.
Is it meant mostly for reading and describing screens or can I use it for inaccessible websites as well? Can I use it to interact with buttons, check marks, inaccessible dropdown menus which on some websites are not recognized by Voiceover at all, etc?
Are there detailed guides or demos how to use and set it up?
Thanks in advance