First of all congrats on your new puppy!
When I first got my puppy at 3.5months, I fed her 1/2 cup of kibble a day. I divide it to 4 meals per day.
Now that she is 5months, I feed 3/4 cup per day, 3 times a day.
I prefer feeding my baby several times a day to avoid making her super hungry and prevent throwing up due to acid reflux when stomach is empty.
But when she turns 10 months I plan to feed her twice a day.
If I may ask, What food are you giving her? and how much does she weigh?