Answer 1

Hi Sahil
congrats on your fresher engineer status. A lot will depend on what your aspirations are. Most CCNA certified guys i know start off in support and ops before they progress to design. This gives them a good grounding on understanding requirements and interacting with the client.
Either way the core Routing and switching certs are required before you will be let loose on any production gear, so I would start there.
https://www.cisco.com/c/en/us/training-events/training-certifications/certifications/associate/ccna-routing-switching.html
Wireless is also very hot at the moment and there are very few skills in this area, so this might be a good area to focus in the future.
Security can be very dry and boring, but for the right person I'm sure it would be rewarding.
good luck on your endeavours