Congrats!:dancer:
Personally I prefer to give hatchlings on 1 pinky a feed every 5 days. On 7 day feedings they will grow a little slower, but still grow. If you buy 10 pinkies and sort them by size, use the smaller ones first, then start using the bigger ones. (It's easier for me because I grow my own and cull at 1 day, 2 days and so on to get gradually increasing sizes). Rather than give 2 small pinks I prefer to give 1 bigger one, as some snakes won't eat multiple items in one feed.
I actually use a digital scale to weigh the mice and sort them into labelled freezer bags.
When you might have more trouble is when your snake is ready for larger pinks then peach fuzzies, finding the right size can be tricky as some shops only have pinks, huge fuzzies, and nothing inbetween. If that's the case for you, you may have to give multiple pinks until your snake's big enough to handle fuzzies.