Hello @sarah-canatsey Thank You for posting your question. My first thought/question is...will these non-credit course shells be used as resources for anyone to access? For example, will these courses have enrollments in them or will they just be available to anyone as long as they know the link? If this was the case, you could make these course shells "Public". Then, you could link from one course to another. Normally, you wouldn't link content from one course to another...especially with students enrolled...because chances are, students in one course don't have access to the other course...and so links from one course to another wouldn't work for them. But, if you have some non-credit courses which are just used to house resources for people and are not enrolling users, then you should be able to link from one course to another without issue.
I'm hoping this will help to answer your question, but if I'm not understanding your question correctly, please provide some additional information so that Community members can continue to help you out...thanks!