Impulse Theme- Need Help Changing the Mega Menu view for Mobile

I am working within the Impulse theme, and I am having trouble customizing the view of the Mega Menu in the Mobile view. When one clicks on the hamburger icon within mobile, our “collection” page automatically shows as open/expanded. Also, the menu looks like a long list- we have men’s product, which is listed first, and then women’s product underneath (screenshot attached with current view). I am looking to do the following :

  1. Select a different group to open when the hamburger is clicked (I want “Flannel Shirts” to open, not “Collections”)

  2. Ideally have the option to have Men and Women side by side at the top of the menu (instead of stacked, how it is now)

If anyone has any suggestions, that would be greatly appreciated. Thanks in advance!