If your baby budgie was raised on a seed only diet it's very normal for him to only eat seed to start with. Keep trying some veg daily and he might try then in time. Romaine lettuce, spinach and kale are all good 'starter' veggies.
Budgies don't drink a lot of water so he will have been drinking, you just haven't see it. If he hadn't drunk in three weeks he wouldn't survive, so don't worry about that.
It's perfectly normal for a budgie to not touch a cuttlefish of calcium block. They will use this when they need it.
If your budgie it sitting on your finger and allowing head scratches then you can take advantage of this to encourage play with some toys. If he has never had a toy he might be unsure so encourage him.
When he's shaking his head, are you seeing him bringing up undigested seed?
What are his poops like today and have they been okay before today?
Do you have an avian vet near you or have you located where your nearest one is in case of an emergency?
Budgies don't drink a lot of water so he will have been drinking, you just haven't see it. If he hadn't drunk in three weeks he wouldn't survive, so don't worry about that.
It's perfectly normal for a budgie to not touch a cuttlefish of calcium block. They will use this when they need it.
If your budgie it sitting on your finger and allowing head scratches then you can take advantage of this to encourage play with some toys. If he has never had a toy he might be unsure so encourage him.
When he's shaking his head, are you seeing him bringing up undigested seed?
What are his poops like today and have they been okay before today?
Do you have an avian vet near you or have you located where your nearest one is in case of an emergency?