When in a session with a coach and say they are watching my screen live as i play. Are there any dos or don'ts they are not allowed to say/do? Or can they advice you how to play completely freely, thanks

Most sites have a one player / one hand rule which essentially means that while a coach can watch you play and comment when the hand is completed, telling you what to do or offering any advice on a hand which is in progress will be against site rules.

Now obviously this rule is almost impossible for the card rooms to enforce, and coaches and players both rely on their own personal sense of ethics with regard to what they actually do. I personally (as a coach) regard it as extremely bad practice, bad for the game and also bad for the student, to "ghost", or tell another player (student or otherwise) what to do in a hand in progress, so I never do this. When I sweat a student live, I will comment on hands as soon as they are complete, but never during a hand in play. I know some coaches do, and some even offer to play for a student during end-game for a certain split, which is most certainly against most poker site rules and also very bad for the game in my honest opinion.

Also, as someone who has taken classes as a student / had rails of my own play, I find it would both a) upset my own game flow to act on any sort of instruction in game and also and more importantly b) leave me with a profound feeling of dissatisfaction if I had won a game based on direct advice taken in hand. I got to the FT by my own mental abilities, I want to be able to feel that way about the endgame too.