Where can I get free tutorial of Nikon d90?

Where can I get free tutorial of Nikon d90?
Where can I get tutorial of Nikon d90?
Where can I get " how to use Nikon d90"?

Try the Nikon web site.

Since you know nothing about it, how about taking a class or reading a book. Read the manual? They are online

Look in the box the camera came in… There's a book in there. It is called the manual.

Get the battery charged, mount the lens, add a memory card, then sit down with the camera and manual. Start on page 1. As you read about things, try them out with the camera.

Do this until you reach the last page… Then start over.

After about 3 repetitions, you'll be ready to take pictures.

You only the manual then read this.