when I press the view cart button that I've created with paypal, towards the bottom of the page that loads is a small link that says "cancel and return to [merchant name]". How do I change the url that it directs to?
You can set up the Auto Return option to return buyers back to your website after they completed the sale on your website.
Here is how: Log into your PayPal account, click profile under My account, click My selling tools, click Update beside Website Preferences, select on next to Auto Return and specify the page buyers will be redirected to next to Return URL and click save. I hope this helps.