If you find a young kitten without it's mother, the most important thing to is DO NOT MOVE IT! Mom is likely out hunting and will be coming back soon. Young, unattended kittens are fine without mom for a large amount of time. If you monitor the situation and mom hasn't returned after a day, you can step in to take care of the kitten(s). Below are helpful resources in he care of neonatal kittens:

What to do

Kitten Bottle Feeding Guide