Why is a header automatically added to a new Template?

[theoD44]

I just purchased Elementor Pro for my existing site. Trying to add a new archive template to build a search-result page. But when I do this (or adding anything new),a header from my current site is automatically added to the new template. How do I change it? Also, how do I go about changing an pre-existing header using Elementor?

Thanks for your input.