S.H.
The parent(s), usually bring their child's foods and snacks.
Unless you are being subsidized and in a formal daycare business and have a license and can then attribute costs to your child care business.
You can inform the parents, that they are to bring their child's food/snacks. Also because, all parents have different ideas... about what they want their kid fed with and what "nutrition" is.
And beware of any allergies.
How many hours, are you watching these kids?
Get them outside in your yard. Unless you don't have one.
Do crafts. Therefore you have to buy a good amount of craft items/glue/glitter/hot glue gun/glue/scissors/etc.
Paint rocks.
Do collages with leaves/flowers etc., found in the yard.
Play tag and play with balls.
Have board games
Teach them how to cook
Do puzzles
Teach them things from workbooks
Get one of those toddler pool things for them to play water games with.
Activities for kids in these age ranges, also means you have to buy supplies and whatnot, to entertain them.
I used to do child care.