Transparent Header
For the transparent header - we suggest using Logo with white colors or with high contrast between the background and logo image.
Solid Header
To have a solid background color header use this class “solid-header” into the menu item > Page Display > Page Class. We used it for the Home page.
Get Tickets Button
This red button was made using SP Page Builder module published on the "menu" module position. We used a button addon there with a dummy link. To sell tickets we suggest visiting JED (extensions.joomla.org) and find a component that has this feature. But if you don't need to sell location seat tickets, only basic entry tickets (even with variants) consider using the e-commerce (shop) component. You can also use the Form Builder component to book and sell tickets. You definitely have several options, including connecting to online services (StubHub, TicketMaster, VividSeats).