Ah. Well, there isn't a way to do many things on console, I'm afraid.
Using cost calculators and other AddOns that scan guild trader prices is one of those things.
Unless you know personally how much materials cost on your console, there isn't a way to calculate furniture prices. On PC, an AddOn scans your guild traders and calculates mat costs based on that, or you can even use community-sourced websites like Tamriel Trade Center to look at serverwide data... but none of those work on consoles, afaik.
"What's the best way to farm furniture recipes?"
The best way to get furnishing schematics for specific styles is to buy the Furnishing Documents from the Writ Voucher vendor. It's quick, and reliable and you can target specific qualities for most of them (e.g. Summerset documents come in blue AND separate purple variants specifically, Murkmire ones come from blue OR purple random item).
That method of course requires you to have tons of writ vouchers. The other option is just looting them. For most zones, the best way to loot them is from Urns, Backpacks, Wardrobes, Desks, Nightstands, Dressers, etc. Barrels, Sacks, Crates mostly contain Provisioning Loot so I think it's a waste of time to farm those. Also, if you can make sure that most of your farming containers are NOT stealing. You can get good loot from 'owned' furniture too, but the loot tables for those draw from the 'Legerdemain' stealing pool, rather than just a 'free unowned' container pool.
Some specific styles have specific locations too. Like Dwemer schematics which come from Dwemer delves and Public Dungeons, or the ultra-rare Ayleid schematics which come from Ayleid ruins. Elsweyr schematics also drop from Dragons and the daily Dragonhold coffer, and Greymoor schematics also have a chance to drop from Harrowstorms.
Also, if you're after a specific blueprint, it might be easier to just buy it from other players. I have no idea how console players can figure out where a certain item is sold (on PC we have AddOns for that too, lol), but there are so many random blueprints that finding the specific 1 you're looking for will take ages.
"Do people buy furniture enough to bother selling?" "What zones might be best for selling in?"
No idea about console, sorry. But on PC plenty of people buy furniture, especially popular ones and new/rare ones. The Alinor/Elsweyr structural items are always popular, so are the filled bookshelves, and usually the new DLC's style sells very well too since most people won't have access to the schematics themselves.
But unless you find yourself a good trading spot and a reliable furnishing market and sell stuff for a long time, it's better to sell recipes for raw profit. The popular zones for trade are usually the 3 Alliance capitals (writ handins, hello), Craglorn, any zone with the Impressario or a current event on, and the Chapter zones. I imagine that's the same for consoles too.
If you're looking for furniture for yourself, I wish you luck. But if you're just looking for an easy way to farm gold, I don't think furniture selling is one of those. Especially since you can farm mats for example without a hard cap on how much you can loot, but shematics are subject to a character-based loot cooldown. So if you loot a purple from a container, you can take a break/switch characters for an hour, because containers will start dropping white shematics instead.
You'd be better off selling Paintings right now, if you can reliably loot them from world/trial Chests.
Good news, you can furnish a house quite nicely using cheap to buy recipes and plans. Not sure of economy on console, but if you set an upper limit of say 200 gold, you will be able to buy half the recipes.
Also, there are numerous merchants who sell furniture for gold, so shop those.