Category Navigation Help

Short background. My aunt passed away very suddenly in January this year. Her husband, my mother and I are trying to continue to keep her business alive, a labour of love and a legacy of hers. I have some knowledge in web design and coding but I have no qualifications and am no professional. Please excuse my questions if they seem easy to find. I am learning the language and my googling and reading tutorials hasn't been able to help me solve this issue. 

The website I am trying to fix is www.bubblebubs.com.au 

Mega Menu Link Issue: 

The main complaint is it is very hard to navigate. So I have been playing around with the navigation bar at the top. We have Mega Menu installed. The links are clickable and go to an empty page (previously they had giant images which I am removing). I would like either of these things to happen.

1.  The links to go away and for the click on the header to just open or close the submenu.
2.  The link to go to a page with every product listed in the subcategories.

What I have done so far:
I have added all the products I want to show up in the sub category, flushed cache and reload the theme. Nothing shows up though, it's just an empty category page with the sidebar.
I've also been trying to click through all the settings but I cannot google/find an option to 'turn off links' in the header menu. 
I also have a Blog link there which I have no idea how she got it there. I am happy for it to stay, but I cannot see it in the Categories area.

Mega Menu Drop Down Issue: 

There is no padding around the menu items and I cannot find any information on padding in the WeltPixel Userguide. I'm sorry if I have missed it but the submenu looks terrible. I tried to add some HTML blocks to pad it out but that wasn't helpful either. I am hoping this is an easy fix.

Thank you so much in advance.