Hello @cibele ! 

Databricks offers the mock test for the engineering associate certification. You can find it here: https://files.training.databricks.com/assessments/practice-exams/PracticeExam-DataEngineerAssociate.... 

For other certifications, I'd recommend investing a few bucks (12 dollars each) on Udemy courses - they usually have 3 or 4 mock tests. https://www.udemy.com/course/practice-exams-databricks-certified-data-engineer-associate/
https://www.udemy.com/course/databricks-certified-machine-learning-associate-practice-test/

Good luck!