they dont need re-potting yet, you could if you wanted to, but they are still seedlings so theres no rush.

with water you just have to use your judgement, as they grow, you will get to know what they need by looking at the soil and leafs. looking at the pictures, the leafs look good and the soil looks fairly hydrated, i would say they are at least a day or two from needing any water.....if you pots have good drainage, when you need to water them, give them plenty, untill it runs out the bottom, let the soil get pretty dry before you need to water again.