How to furnish a very narrow living room,

think small!! Instead of a couch think about two chairs and maybe a live seat.

it would be easier if you posted the plan or something but i would place the couch across from the fireplace with a coffee table between the two and some armchairs on one side, i would place a console table behind the couch and have some kind of dining area or playing area behind that, feel free to message me directly for more personalized i depth help (I'm an interior designer)

Make several seating area. Decide if you want tv above the fireplace or on another wall, with seating across the way. Small proportions for chairs and sofa, small arms and lower profile backs. No coffee table, just end tables. Good lighting. Define areas with coordinating (not matching) rugs. Could one end be a dining area or neat play area if kids are in the picture.

I would float a sofa in front of the fireplace with a sofa table behind it with a lamp or two, and coffee table in front.

Then behind the sofa area, I would make another seating area for conversation and or TV watching. You could also mount the TV over the fireplace. You could also put a couple tall bookcases on either side of the fireplace.

Maybe a desk with a computer in one corner with a couple bookcases.

Don't know what "oits" is?

is the fireplace being used? or just decoration or seasonal?

sounds like my sewing room....we kinda zoned it in 3 sections depending on what tasks are to be done. if you are doing a family or a bonus room, tv area, games and conversation, and snacks/beverage station. my sewing room is 12 by 24 ft.

think love seat by fire, tv or games consul, games table in the mid, snack station closest to kitchen.

Keep the furniture on a small scale...less is better.that is exactly how my den is ,I remove a long sectional couch and put a straight line smaller one in,with two chairs a slim line coffee table with a small area rug underneath

Divide the room into thirds, with an 8’ sofa or love seat facing the fireplace. In that 2/3, have a 4’ across round or square table in front of the sofa. Either put the tv above the fireplace or in the window corner or the wall corner near the fireplace. Use an oval rug between the table and the fireplace. On the long wall, do a gallery of photos, artwork, or memorabilia. You can put a couple of these along the long wall: long narrow table, a credenza, a couple of chairs, a bench seat, a pile of floor cushions. Perhaps you could use one or two of these on the window wall.

In the back one third of the room, make a sewing room, an office, a reading area, a craft area, a dining area, a homeschool room, a playroom, or another area that you have always wanted. Best wishes 😇💞

You could put up a big shelf over the fireplace and then you have a mantle