i cant find solution for my problem
In the Location bar, type about:config and press Enter.
Ooops..... you already do the above in my reply, sorry, forget it...
try the SearchReset add-on, (the add-on resets your search preferences and home page to their default values, and then uninstalls itself)
you can also seek if you have in your profile folder a User.js file. The user.js file does not exist by default. If you have a user.js file and you create the file, don't delete it, if you have not create the file, then delete the User.js file, to see if the problem is there (it happens some programs to create the file).
Also make sure that the new tab page is enabled (browser.newtabpage.enabled = true).
You can check the 3x3 grid icon in the top right corner
See this article about the New Tab page (about:newtab):
Do you get this page if you open about:newtab?
Make sure that you do not run Firefox in (permanent) Private Browsing mode (Never Remember History).
What do you see if you type about:newtab in the location bar and press Enter?
now it's showing the pinned sites but not by default i need to type for every new tab page i open
What are the settings of the browser.newtab.url and browser.newtabpage.enabled prefs as shown on about:config?