How to reduce the space between my header and the submenus?

[Jerry-J]

I have these huge space between my header "Category" and its submenus, I know I'm supposed to change the padding in the HTML/CSS, but I just don't know where to start. Can anyone help? Thanks a lot!

My Website

[Queso]

Hey there Jerry-J! Our Community here can likely lend a hand with the details. Just how much are you looking to reduce that space?