Just some cheapo brass darts in the 20-28gram range would work for house darts. It's generally cheaper to order darts from the UK, even with shipping.
Here's a decent selectionof brass cheapies, if you want it to look nice get a couple sets with different weights/shapes and your friends will have a choice. And if they get more serious about the game they'll want to buy their own darts that suit them.
The primary difference between stuff like these and more expensive darts is material. Good darts are 80%+ tungsten. More durable but more importantly more dense, so the darts can be thinner. Better for tight grouping. I throw
these(play soft tip mostly). But when it comes to shape/weight it's all preference. Best way is to find a local dart shop and ask them to let you try out a few sets, will get an idea what suits you. Second best way is to try some other folks darts at the bar. I used a friend's set that I really liked then went online and found some that were similar looking.
Have seen a few people suggest
Eric Bristow dartsto beginners because they're just a really basic set in all respects. Neutral weight, basic grip etc.
You can order cheap shafts and flights(from front to back the parts of the dart are Tip>Barrel>Shaft>Flight) in quantity on Amazon, gonna need them. And you probably want the longer shafts and standard shape flights for newbies, more forgiving of wobbly throws. Buy a bunch of
o-ringsto use on the shafts so they don't come loose and you are good to go.
The up front costs can be a little daunting if you are trying to get a full nice set up from scratch, but pretty much everything should either last a really long time(darts/board etc) or be dirt cheap(flights etc). So as long as you actually use it the cost:use ratio is really positive.