Matala Theme – want to change menu header order, plus other questions

I have made a ‘custom’ menu and it works properly, but wordpress just puts the menu’s in it’s own random order, even if I create my menu’s in the order I want them, it still puts them in this random order. How do I fix this?

I also I have read many posts about removing the border on the images but none of it works for me, can anyone expand on this?

I have also read many posts about changing the size of the header image, which I would like to do as well, especially making the height of the header.

My website is https://www.elitelearning.com.au