Welcome Lotta, and well done on your C25K.
Each park run is slightly different, but every one I have been to (mostly on my own - DH has only been with me a couple of times) has been friendly. My park run does the briefing at 9 and we then walk to the start, others do the briefing earlier. When I went to visit Blathers at her parkrun I was still parking my car as the runners started
.
The beauty of going regularly is you start to recognize faces and you know who finishes roughly at the same time as you, so you start to run together/have a bit of friendly rivalry/chat
.
On newbies, ours doesn't do a separate briefing, but others I've been to do. And our briefing always repeats the children/dogs on short leads/beware of other park users messages every week. We have some partially sighted runners, so the RD often reminds us of that as well.
Blathers you will be brill, if I wasn't off to Bath on Saturday for the week I would come and visit you.