Are you getting paid to make the thing you want to use my vectors/art/font for?
If yes, then you cannot use them.
Are you planning to sell/make money off the thing you’re using my vectors/art/font for?
If yes, you cannot use them.
Are you a student/teacher who needs something for a class project, or a fan who wants to decorate a backpack/book/motorcyle (true story!)?
If yes, you can use them.
That’s it, that’s a Creative Commons Non Commercial/Educational Use Licence.