I am not from PCP - SIT/Allied Health but allow me to share my PCP -Registered Nurses (Diploma) experience that maybe similar to your.
Most of the time, MOHH will arrange 1 of your prefer organisation for your interview. And if you are not able to attend, MOHH will still try to arrange for an interview but may not from any of your prefer organisation. During your interview, it maybe other organisation that shortlisted you instead of your prefer organisation.
The organisation that you are going for 'day visit' is your prospective employer. While you are assessing if this job, culture and work environment suit you, the person in charge of you (For PCP-Registered Nurses will be a Ward Manager) will be assessing you too. And there are people fail at this stage, so try to be proactive and show you are keen to learn.
During your 'day visit', feel free to ask anything about the professional, career advancement and etc but don't ask about PCP track cause they may not know anything about it and the best is to advice you 'hear say'. And make your own judgement on what they say cause most of the time, they will say 'good' and give 'minor bad' about the trade and industry. It will be good to ask your friends who work in this industry.
The first MOHH meeting is just a platform for you to find out how the PCP programme works. They will tell you what to expect for the sponsorship, your obligations as well as ask you to rank which hospital/ participating organisation you want to be sponsored by and work under upon graduation. They will then try to arrange a one day site visit to the organisation according to your ranking preferences. You will also have the opportunity to clarify any doubts about the programme during this meeting. Basically, you can still walk away bond or damage free as long as you don't sign on the sponsorship acceptance, but that will come much later, after the site visits.