There is a lot to consider.
First where: Not all land can just be 'lived off' of. Many areas are owned by Native corporations and federal agencies. So you will need to find a place where you can secure the right for your little adventure. Parks and wilderness areas can not be lived in, and require permits. You might have luck finding a private landowner who would grant you permission. Researching land ownership by borough is probably best. Alaskans don;t take kindly to trespassers, and even land that appears empty may be owned and you may not be welcome. Alaska is huge, so this first step might take awhile
OK now hunting, unless you are an Alaska resident this can pose a problem, Out of state hunters are limited and you will need special permits. Also you need to be aware of all hunting regulations in the area where you are living. You can not take game out of season, and in different areas there are special requirements. SO start reading the Alaska Fish and Game regulations
and a whole set of regs for fishing
Research the weather and climate in the area you hope to stay, temps in fall can easily be below freezing (depending on what you are calling fall) and conditions can change very quickly.
Also you will need to arrange for supplies, it is not really possible to show up with nothing and eek out a life for yourself. Planning, prep and at least minimal gear are required, so do your homework. Many places are fly in and organizing supply flights and transfers is very important. Many small airlines serve bush Alaska and which you use will depend on where you go.
Really what you are wanting to do is not very realistic for someone without the experience and knowledge about Alaska, Into the Wild is only one of many stories of people going out to 'live off the land' and realizing they were in way over their heads.
I would read ever account I could get my hands on of people who have done successfully what you want to do. Ideally you would be able to speak or work with trappers, mushers, outdoors people, anyone who has done what you want to do to learn what you can from them.
Make sure you are proficient at (at least) the following skills/topics:
basic structure building
getting safe water
navigation (and bring maps!!!!)
reading rivers (Alaskas are not like the rivers outside*)
knots and ropes
wilderness survival, which must include cold weather
hypothermia and basic first aid
edible plants, and be area specific
camping and hiking
food prep, preservation, and safety
if you are a US citizen you don't need a visa. But you absolutely should leave a travel plan with someone, that includes where you are going and how long you will be gone. So they know when and where to send the rescue party.
One Mans Wilderness, Dick Proenneke is amazing!
The Final Frontiersman
And read up on survival, like "Deep Survival" and "the Unthinkable"
I think that maybe finding a remote job, or using a guise would be a much more realistic option for you, and still let you experience being 'out there'
*outside is what we call the lower 48 and pretty much anyplace outside of Alaska