Maybe this will start a flame war, but I got a home in the country at 19 after being raised off and on on farms and a real homestead for 4 years. After bad employment opportunities or a terrible commute to the nearest town, I went to college thinking I would get out, make more money as long as I could stand it and pay-off country land. Along the way somewhere I ended up conserving money living in the city, buying nearly half an acre, a shop and a house that was long-time vacant at the edge of town and started raising tons of veggies, living with my old 4-cylinder paid off truck and generally getting to do a lot of homesteading things like gardening, building outbuilding with recycled materials and canning etc.
I have decided, at long last, although I am not ruling out living in the country someday again, that homesteading in town is not only possible, but desperately needed. We need safe homes without tons of chemicals in the yard for kids to play in. We need kids to see chickens and rabbits and learn to grow veggies. We as adults can also realistically have short commutes (My dad walks to work- I'd even settle to bike!) but still, less than ten miles is good. Especially when even at rush hour it's less than 15 minutes. More time for the garden
This year I am going to try and build a greenhouse in the back with a salvaged furnace and PVC pipe. I'll lay a slip formed foundation most likely. I have gray and green water systems I'm developing and heaps of compost from my masses of plant life. Since most people went to city water my irrigation allotment is artificially high and I have nearly unlimited water for 18 dollars a year and the soil improves each year.
Sure, sometimes I wish it was less traffic noise, but between all my border trees and shrubs and the gazillions of birds and frogs that think it's a refuge of sorts its quite nice to lay in an old clawfoot tub full of comfrey and hot water and look at the stars after working around the homestead. I'm not saying it's better or perfect, but to me, homesteading is to some extent an attitude and you can, as my homesteading mom used to say: "Bloom where you are planted".
I guess I don't see a magic seperation where you are a homesteader one day because you changed everything around you. I think it's internal and I could grow worms and tomatoes in an apartment if I had too, although I'm glad to have a 1/2 acre
I would say: start wherever you can as soon as possible. Don't put it off until you find cheap free land somewhere else. As long as you are alive, improve the soil, the earth and the world around you and you will be amazed at how many possiblities arise each day as you do. Then, when you do get out, you will already know how to can, grow, raise etc.
That's just my take on this, I am not in any way trying to discourage you from moving out to the country, just sharing a perspective that may be of some small help to you or another traveler through this board
~Michael in Boise