@Joey210
You can see at the proflle if there are reviews, and also when they became a member.
When they have reviews, you can click on the host who left the review and see if they left a review also.
At least ID should be verified. When people book for longer time periods I always ask what the purpose is for there stay, before accepting. If the change of the reservation did not process, you can also sent them the change yourself ( "change" option). BTW Adding a "day" means actually adding a night to the reservation, so the check-out date must be choosen correctly.
If the booking is confirmed, it is paid to Airbnb and the amount is in your Transaction History (upcoming transactions). What makes you think it is a scam ?
Best regards,
Emiel