Hey buddy, my seedlings are the first week now. I ...

Yup, start a diary. And seedlings and very delicate. You need to do very little. How they take up most of their fluid intake isn't even with soil. It's done through leafs taking in moisture in the air. So a high RH will suit you better until roots take hold you won't see any drainage from the soil so watering once the week you put it in the soil is enough normally for that entire week. Unless you got serious heat and low RH you don't need to be watering so much. Good luck.

first off you must start a diary and post pics buddy. how could anyone say anything without seeing your plants? all i can say with the limited info is watering too much once shouldnt cause rot. just wait for it to dry out and it’ll be fine. there is not much you can do to make it dry faster except a little higher temps maybe without stressing the seedling of course and if its in a fabric pot maybe set the pot on a towel so it absorbs the excess water and then pull the towel away from under it when its wet. but other than that i wouldnt fiddle with it too much and just let it dry out.