hello and thank you from droping by,

so i want ot build a web app .. a single page kind off app and ii heard its the best for UI/UX kind of thing which is some i like to work on but i have a question for the data and JSON for retrieving ... so when i use code first how i can save people from a login form for example and if i want to make post and article .. m'i in need of a blog ? and how i can do it in SPA ..

Second .. JSON is it for ready data retrieving or for insistent data ?? .. 

i saw i lot of tuts of data repository and JSON but i did not get the idea .. where i get data from ?

 

please help !! i'am really in need of these info