No. You can book as a guest and add the booking to an account later.
No. You can complete a booking with just your contact details, and your confirmation arrives by email as normal.
After booking you'll see an option to link the booking to an account, either with a code we email you or with Google. It takes a few seconds and means you can always sign in later to check your dates, balance or booking reference. See I booked without signing in. How do I claim my booking?.
Email support@pillowcase.io with your campsite name or booking reference and we'll pick it up from there.