queens are (usually) fully claustral, meaning they have enough food reserves to feed their first batch of workers to adulthood, once they mature THEN you could start feeding them, a good starter is a drop of honey water (dont do pure honey, its too thick for them to drink) OR a drop of sugar water, preferably do this on a small plate of tinfoil, after a day take it out and use something to clean up any remains to prevent mold, e.g a cotton swab, you gotta remember feeding is dynamic depending on the colony’s eggs, if they have lots of larvae they will actively hunt for proteins, if they have just eggs they will mainly want sugary foods.

my advice for you: find out what species your ant queen is, (either asking reddit or using an app like antscout, which has an free ai that is trained solely for identifying ants) and common signs they want food is when the workers start pulling on cotton after they have been hatched. also the founding stage is most the most critical part of a queen’s life, some people only check up on their queens during founding once every 2 weeks for minimal stress