New computer using windows 8, old computer using windows 7....

set up my email on new computer according to instructions. Used same email address but the system made me use a new password. I am not getting email on the new computer but I have been getting mail on the old computer. What do I need to do?

PS: I am not a computer geek so please explain in terms a 60+ year old man can understand.

Thank you for any asistance