My screen goes on to the lef side of screen

In unity as I hit play button the game shifts towards left and almost 30% of the game can not be seen. I tried my game on my mobile also as it starts after the unity logo the screen of the game hide sideways the games is running but i cannot see the whole screen. I am new so please solve my problem and let me know what is happening.

select your camera and check if the viewport rect is at

x : 0 y : 0 w : 1 h : 1