Break the problem into smaller chunks.
"I want to take STILL IMAGES of celebrities"
First of all define "TAKE".
Do you mean arm yourself with a camera and seek celebrities so that you can photograph them (STILL IMAGES) and video them (VIDEO CLIPS)?
OR
Do you mean collecting existing images and videos from some source?
"I want to take VIDEOS CLIPS of celebrities"
Same think for the MUSIC.
Do you already have it?
Most importantly, if you are planning on using existing photos, videos and music, do you have the rights to use this material?
You will probably need it. Even if you are not planning to share your video with others, just the act of making copies is illegal in most countries.
"Set the still images and the video clips to MUSIC"
Once you have all of the necessary material in a folder on your computer, you can start focussing on the task of making your own video.
The simplest way to do this is to use iMovie on your Mac.
This is the Apple page explaining how to use iMovie, but there are also many videos on YouTube explaining step by step how to make your first video.
Learn how to use iMovie on your Mac to turn your videos and photos into stunning movies and Hollywood-style trailers.
support.apple.com
As you proceed with the tasks above, you will encounter obstacles. At that point come back here and explain the obstacle in detail. Someone will offer specific help to see you overcome it.
Good luck.