I passed CCSP yesterday.
I used the official study guide and the official practice questions book.
As I'd already passed CISSP that helped a lot.
Not gonna lie, it was a tough old exam, and for sure some of the questions I got weren't topics covered in the two books. Having said that, I understand that you do get 25 'beta' questions, so that could explain that.
The two official books as above are a great place to start, but absolutely make all efforts to study stuff they call out in the book such as OWASP, CSA CCM, NIST and ISO documentation, etc.
The timing of the exam is very comfortable, I finished in 80 mins, so could have theoretically taken twice as long on each question.
My one bit of advice is when you aren't sure of an answer - go with your gut instinct, it's usually correct.
Good luck, it's a great sense of achievement when you pass 😀