Header issues

I have problems when I try to make responsive my header on my web because I find different positions of the menus (icon, menu, search icon, and button) when I change the size of the screen. First of all, I want to try to resolve 3 mainly issues:

1.- I want to center all the header instead of the size screen, now as you can see is on the left side. But I need to keep this behavior (center menu) for all sizes of screen)
2.-I don´t know why (because it happens in other header templates also) when I check the “Drop menu items in More” I find a lot of problems with the submenus, one of them is that don´t show the boxes of the submenus when I hover the mouse on them.
3.-The third issue is when I make a zoom in my browser the texts in the menu disappear as you can see here. And in less zoom, the texts are showed.

I have deactivated all of the plugins and happens the same.

Thanks.

Sorry, My URL is: https://www.tuvisitaguiada.com/prueba/