This is hard to understand, but think of the different aspects of yourself. To your mother you are her son or daughter. To your best friend you are a best friend. To your teacher you are one of a class of about thirty children to be taught. You are a grandchild to your grandparents, a niece or nephew to your aunt and uncle, a cousin to your cousin and a patient to your doctor.
Hindu gods are different aspects of Brahman.
People choose their favourite to worship. Hindu people own models or figures of their chosen gods and treat these images with great respect.