Q: installing/opening QuickTime Player version 10 on macbook air

Hi, hope you can help me out.

I have a macbook Air (OSx el capitan, version 10.11.6) and I want to use quicktime player version 10. So I can record audio and video conversations.

I downloaded and installed it, but when I double click it in the Applications screen to open it, it opens another small version of the Applications Screen where a few applications are lit up.

Does someone know why this happens and what I can do to open and use QuickTime Player 10? To record things..

Thanks!