Dashboard Customization

I am new to SuiteCRM,
How can I make changes to Dashboard look and Feel?
I want to know in which files I need to make changes from developer’s point of view.
Pic is attached I Want dashboard to look like this

The Page that processes and presents the Dashboard is inside modules/Home/index.php.
If you need to have a totally custom Dashboard you can start looking form this point.

Can you please tell is there any tutorial or guidance for making changes in SuiteCRM dashboard??
Have looked from index.php but its bit confusing
So if you can help with some guidance

There is no tutorial, and you are right it is complicated.

The dashboard is extensible, user-configurable, responsive, translatable and dynamic. You shouldn’t throw all that away, try to work within the existing framework and your users will thank you. But if you really have to do it, you will have to understand why the architecture is not straight-forward…

I want to give look and feel as above image. Functionalities i dont want to change at the moment.
So for that which files needed to be taken care?

That is a job for an experienced PHP developer. It’s not a task for a beginner. As I said above, there is no tutorial, and there many files to change. I don’t know ho to do it, and even if I did, I wouldn’t have time to explain all of it to you.

Are you able to start looking into the code and find out? See how the current screen works and try to apply your changes: