Android SDK Manager does not show packages to be installed, on Windows 7

[tomyf]

I'm new in android programming and since my experience was about Qt Creator I tried to use that for android programming so installed Android Studio 2.2.3. The following is the path and contents of SDK folder:
http://imgur.com/a/a1TXI

My problem is that when I run SDK Manager, it does not show packages for installing.
Only the following:
http://imgur.com/a/wpyl1

Is there any way to make this issue fixed please?

 

[tomyf]

The error I get when creating an Android Virtual Device (AVD) is:
No CPU/abi system image available for this target Android Studio.

If the problem is of packages, shouldn’t I download and install them manually? Because I think SDK as itself shows, is up to date and downloads nothing else.