What are the problems faced by entrepreneurs when setting up a business?

how to set up the market and supply the customer as per their demand

I would also add:

1. Entrepreneurs often limit their horizon to 6 - 12 months rather than 3 - 5 years. In other Words, entrepreneurs should develop strategic plans, strategies and tactics with a 3 - 5 year horizon.

2. Entrepreneurs tend to underestimate the amount of capital they will need to achieve their 3 - 5 year goals and objectives. Hence, the need for a 3 - 5 year visible horizon.