The type of fishing you are asking about for subsistence/personal use isn't longlining. It also depends on the type/species of fish you are after as to the type of gear you use. What you are asking about is known as a skate.
Subsistence caught ground/bottom fish such as halibut, cod, flounder etc are caught on a skate basically made from longline gear.
My halibut skate is made from a length of commercial longline with a loop and shackle on the end for the base anchor. I measured off approximately 25 fathoms of line and tied a second loop for a shackle and anchor. The length of line between the two anchors is what is known as the ground line.
To the groundline I attach stainless wire safety pin looking clips (commercial halibut&cod gangions) that have 24" leaders with pre-baited, self-setting circle hooks tied to them. They are set about 2 1/2 feet apart so they won't tangle in the current while on the bottom.
From the second anchor to the end of the line measures about 30 fathoms and a marker bouy with my NOAA issued Subsistence Halibut Registration Card (SHARC) number is attached to it.
Anchors are made from 3# cement filled coffee cans that have about four links of heavy galvanized chain in it for hooking to the shackles. All the gear is stored in a commercial longline tub for deployment.
The way it works, is we attach the first anchor and as we feed line over the side of the boat we clip the pre-baited gangions on, then attach the second anchor and feed it over. When the second anchor hits bottom, we power up the boat and drag the anchor a few yards to make sure the groundline is streched out and the whole mess lying across the tidal current and the remaining line with the bouy attached is pitched overboard.
We come back and check it after a few hours and hopefully it'll be loaded with halibut, rather than cod, sculpins, irish lords or bullheads. My fishing spot is only about 5 minutes out of the harbor in the cove.
For salmon, you'll need a set net and either fish along a beach or a freshwater river or creek during the runs.
A bud with a commercial fishing boat will do too.
Gear can be picked up from the commercial fishing suppliers and there are quite a few commercial fishermen you can scavenge gear from. I got mine from a pile that had been discarded.
I couple of things. As a Fairbanks boy I do not like, nor do I recommend anywhere along the coast of AK as a place to live. It's wet, windy, damp and makes my bones hurt. I prefer the woods and rivers of the dry interior, particularly the Yukon and Tanana River Valleys, to anywhere along the coast.
Furthermore, you'll need to buy or have access to a boat or skiff to be able to engage in this method of fishing. There is a rather large initial investment when getting started into this lifestyle and the best way to learn is participation with the local folks who've been doing it for the last 30,000 years or so.