i just got my parakeet a week ago and it is about 3 weeks old i have no clue if it is a boy or girl yet and want to name it here is a picture. also how can i make him/her feel at home and not scared of me
You could pick a unisex name. I have a conure, and I was told that I either have to have a dna test done or wait until he/she matures. (note I am a new parrot owner, so you might want to get some info from other people too)
If the cere stays that colour or goes a darker blue then you have a male, if you have a hen it will turn to a brownish colour. You will have to wait roughly another three months (assuming you mean your budgie is three months old not weeks like you said) before you'll be able to sex him/her accurately.
If you want to know sooner you can get your budgie DNA sexed as the previous poster suggested.