They do tend to panic when left in the dark and there is a noise or a flashing light that they do not recognize. When the main lights go off in my birdroom, a low wattage bulb is left on which gives the birds sufficient light without keeping them awake and chattering. It also helps to avoid the possibility of a hen leaving the nest in the night and being unable to find her way back, leaving eggs to cool or chicks to die from the cold. You then have to decide whether you are going to breed for pleasure, colour or exhibition. This will make a great deal of difference to the type of bird you buy and the price you pay.
Most people begin because they like the brilliant colours which they see in the budgerigar.
I did myself, and went to a pet shop and bought the brightest colours I could find. When I realized that there were such things as exhibition budgies and got involved in the show scene, I tried to combine the two requirements by keeping rare varieties, which were usually brightly-coloured. I did quite well with them, but as time went on, found that if I wished to compete in a significant way, I would have to reduce my rares and go more for the standard varieties. Each year now the rares get less. So, if you are of a competitive nature, then buy the best budgerigars you can afford from reputable breeders.