First parking charge notice, in need of advice

I’ve only been driving since february and haven’t had a parking charge fine. I’ve just gotten a letter through the door from BPA and Parkingeye.

Are these both serious companies? and not the ones like that it’s not a legal charge it’s more of a civil charge like an invoice.

I’m from Scotland but the charge was when I was at a hospital in England. I was in a private car park managed by Parkingeye for 13 minutes when loading my car with my stuff and my dad who had just had a lung transplant and he had lots of bags with medicine.

Just need some advice and some help as i’ve never had a parking charge fine before?

Thanks!!