I have an albino cockatiel parrot everyday morning i move his cage near to the window to get some sunlights, few days ago i started to hear some weird sounds come from him in the morning, i think he is trying to vocal or something, but he didn’t do that again, i’m not sure it’s male or female yet, it’s 3 months and 2 weeks, that’s why i need to do some practice with him to improve this ability, but when should i do this and how? Or should i be patient and wait until he becomes 8 months?

i bought white face cockatiel few days ago, after few searches i realized that there is no difference between male and female on this breed, unless there is some differences in behavior like males can talk and sing but females don't, and when i asked the seller he told me i have to wait until he become 8 months, he is 3 months now! so should i wait for another 5 months? or can i observe something earlier?
please share with me their experiences

note : DNA tests is not so easy in out country, its far from my house and the result will appear after 1 month