How to enter into UI/UX designer field being an B.E with 5yrs of experience in non tech jobs,

Yes ofcourse you need a portfolio. 3-4 projects is more than enough to get an entry/ mid level job.

Try redesigning some apps that you think it can be improved.

But the thing is the design market is highly saturated now. You can survive only if you are passionate and have a good network.

Don’t