Almost all applications are not available in App Store

Are you signed into the Georgia App Store? Based on your screenshot, it looks as if you're in the App Store in an English-speaking region. If you've inadvertently changed app stores, that would explain the problem. You can only download apps from the store in your country/region.

Do you mean Georgia, the state in the southern part of the United States? Or do you mean the Republic of Georgia?

Glad it helped.