Dieline And Background

Good morning Abode support community, So basically I'm trying to add a background to my dieline for a college assignment and I downloaded the dieline from template maker and I realized that some of the lines on the thru cut of the dieline weren't actually connected so I couldn't do a background with a clipping mask like normal and I did use the pen tool to connect all the lines properly and then I discovered that on a my thru cut layer none of the lines were actually connected so I've been trying to connect them and I'm kind of struggling a bit to do this so is there any easier way to do this cause it's really frustrating. I can send a short screen recording a little later when I get home to show you what I mean if you would like just let me know.

Thanks so much In advance!

vevegirl22