To get a job as a Big Data engineer, you need to have a good big data certification in your resume. Do some research on the internet for the best big data courses. You can take up either offline or online courses to learn Big Data. Go through their course curriculum and assignments. Some courses offer a few free classes. Just attend those free classes and check whether their teaching suits you. Enroll the course which you liked most and try to complete the assignments on time.
I would suggest you this Big Data Hadoop training course by intellipaat if you want to get big data certification.
You can watch this video on Big data certification to have a better understanding: