In header.php you can see the same code that appeared on your page.Pls go to that code line in header.php and you can see space in between the angle bracket and the question mark,pls remove the same.
The sceenshot given by me is self explanatory.
Since your primary menu list is lengthy unless you reduce the list,it will be difficult to allign the menus’s as per the screenshot and also it will affect site’s responsive feature.
Pls try to use dropdown menus So that you can use the following custom CSS.
Also pls remove the primary menu custom CSS that you have applied before