You go girl! Good for you. I think it wise to keep a part time job because there is always something you need money for. If you don't need everything you get paid, then sock it back because there will be something come along and claim it. Always better to have a nest egg to get you through emergencies. You might want to research raising chickens. You get eggs to sell, meat, and baby chicks. What is the market in your area? Cattle take a LOT of room and are big to handle. Not to discourage you, but you might want to consider goats or sheep because they are smaller and can be easier to handle.
If you want to raise a lot of your animal feed, look into mangel beets www.rareseeds.com they have several different fodder type beets. Also look into pumpkins and winter squash. Both keep well in the winter and are easy to raise. It would not make a complete ration, but it would help on the feed bill. Also Daikon long root radish, the greens as well as the radish are good feed. www.bountifulgardens.com has grain seed. They carry a lot of the old heritage seed. While you wouldn't get a lot in a seed package, if you raised it one year, the next year you could plant a pretty good patch.
If you put a metal roof on your small house, get a heat barrier. It is available from places that sell metal roofing. It will make a 15 to 20 degree difference. If you build it with a gambrel barn type roof, you can make the loft your bedroom.
Mosey on over to the easy garden forum, link at bottom of page, for anything you want to know about raising a garden. Lots of good info there and the people are very helpful. You could plant permanent plantings such as fruit and nut trees, berries and grapes. Then plant your annual vegetables and you would eat like a queen.
We are raising 3 pigs right now, they are going to slaughter in a few weeks. One is ours, the other two are sold. You night raise a couple of pigs the first year, just to check your expenses, then do custom raising for people who want good meat. That's where a big garden comes in handy!