Hi @Roz4. I am also learning about this all and sent a similar message to a guest a couple of days ago. Mine was:
"Before I pre-approve your booking, can I offer some advice? You sound lovely, but I see from your profile that you don't have any reviews yet, so it's really important that you complete your profile and verifications. Unfortunately, us hosts hear a lot of horror stories about guests without reviews/verifications and therefore many hosts would be reluctant to accept bookings without either.
I understand that you can't build up reviews until you stay a few places, but I suggest that you add a profile photo, a short description of yourself and get at least your mobile number and email (but preferably also your (SENSITIVE CONTENTS HIDDEN) profile) verified by Airbnb as soon as possible. By the way, verifying your (SENSITIVE CONTENTS HIDDEN) profile does not give users here access to it or allow Airbnb to post on it!"
I didn't realise the bit about a social media site verification would be hidden when I sent this, but it worked a treat as, within a few minutes, she had done all the things I requested and sent me a note thanking me for the advice.