Fast Buds Purple Punch, first grow ever.

this week was fun but theres too much information online and i couldnt tell if i was overwatering or under watering XD the shell fell off pretty quick after sprout but there was some leftover stuff that prevented the first leaves from opening. i lightly proded the sides with a toothpick and it popped right open. my ph meter just came in today and im not sure how accurate it is, so i might have to try calibrating it. ive been using a jug of distilled water from the store for now, but i wanted to try using tap water once thats gone. any advice is greatly appreciated !