Everyone's got a learning curve, and you're at the steep beginning of yours. Go slow and you'll do fine; start in abruptly, as you appear to be contemplating, and you'll be uncomfortable at best, in actual danger at worst.

What this means in practice is that you want to experiment with equipment and techniques when and where the consequences are reversible and not severe...or under the guidance of someone experienced. If you're going to spend the night outdoors in below freezing temps on a groundmat of fiberglass insulation, you really want to do this in your own backyard, or at least within easy reach of friends and the refuge they'll provide when it all goes sour. As it will, per the explanation above.

I'll add only that there are several varieties of outdoor experts. Some pursue hobbies involving spending a lot of voluntary time outside in inclement weather: fishers, climbers, campers, bicyclists, motorcyclists. Quite a few learn their skills in the scouts or the armed forces. Others know how to make it all work for little or no money: these folks are often referred to as "homeless," or "bums." It's the latter who really have the information you're seeking, and believe me, they won't often be found lurking here on the Hubb. You'll find, though, that they know where to get free clothing, bedding, food and shelter, how to stay dry when it's wet and warm when it's cold....and how to stay out of reach of those who prey on such people, an important consideration.

There's real skill in it, and (see above) a steep initial learning curve, but there are lots of folks out there doing it. Some are pretty messed up, but others are fine, often fascinating people. It might not look good on your resume, but some of what you'll learn is readily transferable to a more conventional life.

I speak from the perspective of one who was, at various times long ago, homeless and destitute--and who has ever since made lifestyle choices involving living outdoors under more comfortable circumstances. Don't make the mistake of thinking that the salesclerk in your local outdoor recreation emporium will be able to teach you what you need to know about living in the open without much money. With occasional exceptions, only people who've actually lived that way will know much about how it works.

In framing it this way I hope it's clear that I don't mean to sound critical of any ideas or advice found here.

Hope that helps. Good luck with your journey.

Mark