Learned to use a media query to give the site a nice 50px margin on the left and right, but on small screens (cell phones) on 10px – looks good on computer, iPad Mini, and still good on phone browser.
My goals are very humble - and this was very simple. Setting initial scale with viewport to 1 so my iOS stuff doesn’t make things tiny was good too. One step at a time.
Good luck! I personally find using CSS Grid as your site’s main layout is a cheap way to make a seperate “mobile” version by just changing what order its displayed in.