Should i be a UI design expert to get into good product based companies as a product designer

Knowing both means you can ideate and execute. More opportunities too, as companies would prefer an all rounder if they are on a budget. To know from someone from the industry, checkout Harish Sivaramakrishnan’s posts on Linkedin.
You can start with some basics and slowly work your way through. Perhaps try replicating a few screens from dribble or so. Figma can be intuitive, so you might start liking it too.

Yes.