It depends on how they have been raised. Male or female can be just as friendly. It take a little while for them to trust someone. They all have different personalities and some are going to be friendlier than others.
Some female ones may be mean and some may be nice.
Parakeets that live in groups are usually more friendly. In the wild, parakeets live in flocks, so it's best if you buy them in pairs.
Your parakeets may have not been male and female they might have just been 2 females or 2 males.
Well, if parakeets are healthy and happy both male and female will chirp alot. That being said, male and female parakeets will often screech if they are not happy or if something like your music being played too loud or a cat is bothering them.
both male and female
By there noses. A males nose is blue. A female is pink or a light peach
You should start hand training your parakeets as soon as they can stand up on their own. They are friendly birds who are easily socialized. A single parakeet is easier to socialize than 2 or more birds, because they will socialize with each other rather than with you.
I don't think so. I read that adult female parakeets noses are brown and that adult male parakeets noses are blue. But, young female parakeet's noses are "bluish" and a young male parakeet's nose is pink.
Budgies, parakeets, and cockatiels would be your best choices.
that's normal
singing is a way of comunicating for parakeets and a way of showing comfort, the male is probably not used to see a female...give him time, he'll get confortable in 2 weeks latest.
yes
Parakeets do not give birth to live babies but rather they lay eggs. Each batch of eggs is called a clutch. After the female parakeet lays the eggs she lays on them to keep them warm until they hatch.