How to make a responsive website if there is only one layout?

Question

Layout

Gave one layout per 1920px. And if you reduce the browser window, then the elements float on top of each other. What to do with these elements? Reduce fonts? Do it at your own discretion? And what media pixels to put? Up to 320px check?

Answer 1

It was necessary to do all the elements of the lines with float: left and without a reference to the page width.
Fix it.