Negative points

Hey everyone!! Happy Sunday ! So I’m really well you can say VERY new to this app ,and mystery shopping in general. I downloaded the app and decided to give it a try. I scheduled myself for 2 shops but unfortunately due to a family emergency and being really under the weather I had to cancel the shops. Right after i scrolled to the top and that’s when I seen my points were in the negative I wanted to know the purpose of the points and can you or someone explain to me how i go about fixing this !also are there any shops coming up that require travel or hotel motel stays ? When is the best time to look up for new shop work

thank you
Tiffany