Mobile First Workit Landing Page using HTML & SCSS

Hello, this is my first time working on "real projects" after enduring a useless 12 month Front End Face-To-Face Course that didn't prepare me for the job.

Here's a few questions I'd like to ask to the community:

• Am I using HTML5 elements well?
• What's a better way to organize SASS foldering? Did I overdevelop the page by choosing to use SASS?
• I'm having trouble with making optimal responsive layouts, I find myself constantly tweaking dimensions and positioning. Could you point me to some resources that could make me improve?
• I reeeeally don't like using absolute positioning in my projects. Is there a better way to layout decorative and/or overlapping elements?

Thanks in advance!