Help me please :)

New to hubspot and need to import my excel sheet. I have multiple contact names and email address from the SAME company that I need to include but in some cases they have taken the same safety course. So i need to have the main point of contact, the actual trainees names and emails and then same pr different course names they have taken. How can I set this up first in excel, and then upload into hubspot in a way that it doesn't see this as duplicate info? Thank you!!!!