Yassin Hajaj wrote:- Am I doing a mistake by taking the Java SE8 Associate instead of the Java SE7 one?
Not at all! I think the decision between OCA8 and OCA7 mainly depends on the availability (and your preference) of resources to study for the exam. Here you'll find an up-to-date overview of the available resources. You probably want to take the OCP certification exam as well and then it depends on the time frame. At this moment there are no study guides for the OCP8 certification exam, only for the OCP7 one. So if you want to become OCP certified this year and want to use a study guide while preparing, you don't really have a choice and have to opt for the OCA7 and OCP7 certification exams (you can't combine different version certifications).
Yassin Hajaj wrote:I was just asking if there were websites or even books with fakes exams.
If you have read my previous posts carefully, you'll find a link to a topic with an up-to-date list of resources (books, mock exams, videos) you can use to prepare for the OCA8 exam. Both OcajpFaq and OcpjpFaq will also have links to all kinds of study materials like study guides, mock exams, and so on.