Course of action mold? To much water? Remove plants?

First of all big thank you to all you experienced growers that take time to reply and share knowledge it's a HUGE FKN HELP. Between this and the Google there is a ton of info available.

Last year I was given some 3-4 week old plants from a friend , I hadn't grown weed before only mushrooms but was able to do the adequate research to not only keep them alive but grew some some pretty big plants ( I'll attach pics) (I'm aware or alot of my mistakes I know there bushes lol)

Because of that good experience I invested in a indoor set up,
I bought some of our local hydroponics store house brand seeds while waiting for a quality seed order from online to come in pics are them .

Although I have now done monthes now of growing research and shit , I didn't realize that seedlings required so little water ( my opinion of so little ) and have overwatered some of them (see all pics) (heard u guys like pics )

it looks like now as a result some have an infection, and I just need to know best course of action I'm not mad to throw them away or bring outside and monitor them ,
also one plants a little bit light but I'm thinking just my dumb overwatering

You will totally be okay ive done this exact thing before lol, just let them dry out completely before you water them again. Since you have them in somewhat decent sized pots for seedlings maybe try to just water them right around the base for the next watering or 2. (I prefer to take solo cups and poke drainage holes in the bottom of them for my seedlings, it promotes faster growth off the start, but only leave em in solos for few weeks or until leaves extend outside top of cup). Just make sure from now on you stick your finger all the way in till your middle knuckle is buried to feel for moisture before watering.

You're fine, everything looks ok