shopify by default adds an added app block to all pages where template is default

[ashik23]

2 problems:
1) I created an app block and when i added that app block which basically adds a new section having some designs , ui  in it.  to a page ex: "test page" . shopify adds that app block to all other pages where template is default template. like if i have a page called test 2 then it also adds that app block to page 2  too. I have tested other apps app block. it does the same . how can i fix that? . i want it to show up on a page where i added it !
2) Beside , It take a default width which breaks my design of that app block . how to fix that?