1) Is the prayer of male and female or is there any difference?2) What is the ruling for following the four Imams?3) Are we allowed to work in a supermarket?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

There is no difference between the way of performing the prayer of a man and a woman.
However, some scholars are of the opinion that it is better for a woman to adopt in Ruku and Sujood a position that completely covers her body, leaving none of her body exposed, but there is no supporting evidence for that as per our knowledge.
The ruling of working in a supermarket is subject to the work to be done. If the market sells alcohol, pork or other forbidden things then working there is forbidden, since a worker helps and shares in these forbidden activities; otherwise, working there is permissible.
Allah knows best.