Instant tracking

Hi team i am working on the multiple scenes – its like scene 1 → contain image tracking
scene 2–> contains instant world tracking
issue – 1:
i wants to switch from one scene to another scene by clicking the button image in canvas
what’s the problem is → in instant tracking the starting it self model is coming before scanning the image tracker
issue --2:
i am using the zappar camera and revomed the default unity camera but it shows error of there is no camera

so please kindly give the solution for the issues