I am new to oralce exams. I am thinkinb about taking the SQL/PL-SQL exam this summer. I do not have any professioinal experience on oracle but I took a database class and learned some basic SQL stuff. Is that sufficient background to go for the very first exam?

Here I have some questions about the exam.
1. What would be a comprehensive book for the first exam 1Z-001?

2. Is there any free mock exam questions availale over internet?

3. How long would it take to get the first exam?

4. What would be the benefit of the first exam, if that is the only one I take? Is it going to help me for finding a job?

5. Will I get any certificate from oracle for only one exam?

Thank you for your tips very very much.