Hello, Dear Customer!

Thank you for  your question.

By default, the top section in theme under them menu - is intro section.

You may edit it via  WP Dashboard => Appearance => Customize => Homepage Settings => Intro Section:

https://tinyurl.com/28c4cp25

It is possible to assign custom image for this section, button, text, etc:

https://tinyurl.com/2d494oht

https://tinyurl.com/2bhvpbu7

https://tinyurl.com/2xnal3jo

If you want to use several slides, hide this intro section: https://tinyurl.com/257995an

Then please click WP Dashboard => Appearance => Customize => Homepage Slider:

https://tinyurl.com/2763tms5

Click each slide and expand settings: https://tinyurl.com/2xvj2ktv

Best Regards!

Hello, Dear Makhijani Gaurav!

Thank you for this nice question.

Please open this page in Elementor and select 1-st section in Navigator tool:

https://tinyurl.com/28jklp34

Expand "Style" tab: https://tinyurl.com/2y8o3zom

Replace this image and publish changes, then check results at front-end.

In the attachment for  this post you may download the original background image. it is transparent. You may modify it according to your purposes.

Best Regards!