remove space in header

Can you please advise me how I can remove a lot of space what I have in the bottom of the page please?
I have the hidden header but I still have an empty space there and also a search field which I don’t want to have
Thanks in advance

Hello there,

I hope you are doing well today.

Could you please provide a link to your website so that I can inspect it?

Best Regards,

it’s on a local server now
So i will be back when I put it on a server than