How do I Copy Fields from One Form to Another

How do I Copy Fields from One Form to Another

This is probably a stupid question, but I am very new to database creation and have no experience with scripts or anything; but I am trying to learn.

I have two forms: Existing_Activities_University and Contact.  They are both Subforms to University_Data.

In the Contact form, I have a checkbox field that I would like to have show up in Existing_Activities_University. I would like for this to be dynamic, i.e. if I add or change fields in the checkbox in Contact, I would like the field in Existing_Activities_University to be updated as well.

I am sure this is easy for all the experts in here, but please explain in layman's term for this noob.

Thanks for the help!