They are way too young to tell. I have a 2 year old male with a bright pink cere like your blue bird, and I have a female of 2 years with a light blue cere with white rings around her nostrils. At about 10+ months old they will mature enough to know for sure...
I thought my male was a female...
You just need to spend a short period each day with your hand inside his cage, with your finger outstretched saying "step up" while holding your finger above his feet and against his chest. Make sure you have a treat ready for when he steps up, like lettuce. I spent 15-20 minutes each day just...
I'm not sure exactly what you're looking for in a bird, but both budgies and green cheeks are playful, and both can talk, though green cheeks are definitely the quietest of the conures, and budgies,if they talk, aren't the best at it. I have had birds all my life, and I currently have a bunch of...