Getting Paypal express to work in sandbox

[Team1Shopping]

Hey guys,

 

So I'm building this site as a project for one of my classes, and I cant get paypal express checkout module to work. Whenever you go to checkout something, it just takes you in circles and never lets you actually complete an order, and I think its becuase paypal isn't set up right.

 

Of course, this is all for a class, so I don't want it to be actually operational, but I've set up a paypal business account and put in the api credentials in the paypal module, and set it to sandbox, but when I test it, it says failure. Any ideas?? I really don't have any web experience, and our professor is something of a tool.

 

Thanks in advance!