Personal Portfolio Page (help with margins and responsiveness)

Hello, fellow campers. I just started FCC recently and I’m loving the tutorials. I’ve began creating my portfolio page and I’m having fun at the process, but I’m struggling quite a bit with the margins of background images as well as the sections within the page. I also can’t figure out how to make the page more mobile friendly. Any other feedback would be so appreciated.

Thanks again,

Use bootstrap grid - it is responsive as well as the whole bootstrap framework.
Useful tutorial :