You mean side-by-side just for the icons like this?
The flex layout applies to each element and since the icons are different entities, they will not align as a group. I recommend adding those social icons as Global block (please check this https://theme.co/apex/forum/t/global-blocks/24723)
Then add the global block element within your footer just under the inline menu.
But make sure you align your icons within the global block builder.
As for the spacing, please inspect your second section and set the padding and margin to zero. Or at least smaller value.