Starting your career in DevOps is a great decision, there are a lot of vacancies and very few people trained, hence easier to get shortlisted and as demand increases pay obviously increases.
So, number one, Knowledge is obviously needed but certification is an added advantage and increases the chance of getting a job.
It takes almost two months to learn and practice the basic concepts of DevOps. The rest comes with hands on experience.
Finally let me guide you to the salary structure.
If you're a fresher it mainly depends on the company, you get into and your educational background.
If you've perused your studies from a known reputed college like iit, nit etc. there are chances you get placed in companies like google, Microsoft etc. and your pay would easily be 15-18LPA.
If you've studied from any other college and got placed in an MNC like TCS, Infosys, you can get up to 3-4LPA
You can get up to 7LPA in a product-based company provided you've got the required skills and knowledge.
All the best!!