Water my plants question??

i need to know how much to water my plant it's currently still a seedling but it's getting taller a little and the bladed leaves are getting a little bigger each day I know you're supposed to water it when the first once of soil is dry then wait till it drugs again and repeat this process, and get 20% run off, now my question is do I water it with a certain amount of water? And if so how much should I be giving my seedling?, then veg? Then flower? This is the only thing I'm really co fused on! Please someone help lol!

There's no specific amount, just try not to over water it in this stage, I got a couple plants of all different sizes and my small ones I barely give them any but the medium and big ones I can just give a shit ton and they seem to love it