transfer

Be certain your iPhone 7 has a current iOS version. Be certain it has sufficient storage. It should have at least as much as the iPhone 11.

Be certain it’s like new software-wise.

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

Then:

Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support

Why not?

You have to give us something to work with if you expect help.

doc_ansari wrote:

But i am not able to do it

We need much more information. Your comment is like visiting a doctor and saying “I am sick.”

Perhaps you’re not aware the blue areas in my original response are links to web pages you should read and follow.

First, thank you for your service.

Simply follow all the directions given in my first response above. Again,the blue areas lead to linked pages with detailed instructions.

OK, then I don’t know how to help you further.

Good luck.