First of all I would say I am lucky to score 85% in my first Solution Architect Associate exam and from which almost 70% I would day credit goes to https://thecertschool.com/ quizzes I have practiced until I got 100% and on exam day I had 80 question and just because I had given extended exam and more minutes to complete.
You should also have the knowledge too and do read FAQs. Mostly questions comes from EC2 EBS and S3 these are the backbone of Solution architect exams and just have to go through VPC too.
i wasn’t so confident only to study until i practice the quizzes and not only I wanted to pass but these quizzes gave me good understanding too. they do update the quizzes on daily basis coz now I just noticed they added one more quiz so keep up the good work.