Hi djh0815,
Welcome to the Heartland Owners Forum and to the family. We have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.
You probably need to post some pictures of the hose and where it is hooked up. It kinda sounds like maybe a hose to blow out the water system for winter protection, but hopefully someone else will have better info than me.
For your fridge, if you are on 120v power all the time, a regular fridge would work, but if you are not, or off 120v for more than 4-5 hours then you probably need to stay with about the same type. Not necessarily bought through Heartland, but available through multiple sources.
Be sure and check out our Heartland Owners Club. Join us at a rally when you can and meet lots of the great folks here and make friends for a lifetime.
Enjoy the forum and your new to you unit.
Jim M
Also, you may need to make a couple more regular post before forum will allow you to post a picture.