Need Custom Code to do some small fixed

Site URL: https://nourishedyoung.com/

Well, I have a SquareSpace website and I need very small tasks (One liner code) to be done but its not working for me.
This is my site

https://nourishedyoung.com/

1-I want to make my header transparent so background image would show behind the header as well

2- Background image of first section does not show on mobile, it actually shows but cropped out, How can i show it full?
Here its how it shows
https://ibb.co/GCp6hw5

3- I want to make these pictures smaller

That's it. If you can help me then It would be a huge FAVOR for me. I really Appreciate it,.

Thank you.

Can Anyone please reply this ?

#1. #2. #3 It looks like you fixed?