Is it legal to write about celebrities in my website?

You can "write about" them. You are likely to have difficulty finding "Creative Commons" images you can use legally. But you can write your own words to comment on things.

You can write what you want. It's called "free expression."

As long as you don't publish defamatory lies or post copyrighted material you should be OK.

The only problem I see is your belief that there are "creative commons" images of these people.

I expect you will get in trouble. Big trouble.

You can write basically anything you would like about them with the exception of lies meant to defame or slander them.

Why would you think it would be illegal? Only a million of them exist already.

They are public figures, anyone can write about them.