The message I'm getting is the breeder kinda "quit" feeding the babies, and handed them off..
If that is the case, PLEASE get these babies to an avian vet, or an experienced hand feeder! Hand-feeding babies can be incredibly dangerous no matter the circumstances, let alone for someone with no experience.
I'm not trying to put you down, or be rude, but for the sake of the baby birds please take them to a pro. One day old? Should be fed every couple hours, with a specific formula, at a specific temperature, in specific amounts. I'm so sorry you were put in such an "on the spot" situation. I had to hand feed my Alexandrine once. ONCE. And I was so nervous. Luckily the hours of research helped me feel somewhat comfortable with her one comfort feeding.
I hope everything works out for you and the birds, best of luck.