1. what do i use to line the bottom of the cage?
I use newspaper.
2. what kind of food can they eat? i'm getting 2 babies
There is quite a range of food available for budgies, as apart of their everyday diet and for occasional treats.
I give my budgies daily: seed, fresh veg and water and once a week either a piece of millet, arrowroot biscuit, sunflower seeds or honey seed stick. For more info on food check out the FAQ's.
3. is buying in bulk better? for 2 budgies?
Refering to seed? For just two budgies I don't think you would need to buy in bulk. When I just had the two budgies a 2kg box would last a couple of weeks and that was changing the seed daily.
4. do they really need to have coal? my friend told me they need it to digest properly
Sorry, can't help you out on this one.
5. what is cuttlebone?
Cuttlebone is a source of calcium, but I find my budgies prefer to play with it and chew it up rather than 'eat' it.
6. do their wings really need to be clipped?
They don't need their wings clipped, but their are advantages to it (as well as disadvantages). It really is a personally choice. Definitely worth weighing up the pro's and con's before deciding.
And if you do decide to get their wings clipped, make sure it is done by someone with both the knowledge and experience on how to do it properly, such as a vet.
7. how often should the cage be cleaned?
I do 'daily cleaning' which involves removing the veggies, changing water and seed, clean my cage once a week and every month I do a thorough clean out were everything gets a good scrub.
8. if i let them fly around the house, will they come back to the cage?
If you work on taming them (i.e. getting them to 'step up' onto your hand), it might make getting them back into their cage an easier task.
Though if you let them out to fly around, I would assume that eventually they would return for food, water or to roost.
But perhaps start off small and only allow them to fly in one enclosed room.
I hope that helped, I answered to the best of my knowledge and from personal experience with my budgies .