Theme does not look responsive on various devices

Hi Richie,

My site dnvoice .com looks ok on desktop and older laptops from 5 or 6 years ago, but on almost all other devices such as new laptops/tablets (no margins on either side…text touches both sides and no empty room on either side), cell phones (top ribbon shows no links, all sections from the right side bar are one under the other in a long column…it doesn’t look like the regular site).

What can I do to show some empty space on both sides on laptops/tablets and to make the site appear like a regular site on cell phones?

Please advise. Thank you.