Your mix look extremely wet and excessive water causes roots to rot and be suffocated and the leaves die as a result. So how and how often are you watering them? Perhaps you do not have enough drain holes in the cups. What mix are you using specifically?

Have you fed them yet? With what and how much?

Dave

I just watered them before taking the pictures actually! I give them about 1/2 cup of water per day, and yes I have 3 holes on the bottom of each. When I planted the seeds, I used organic seed pods, transplanted them to the cups about 2 weeks ago and used organic potting mix

what do you mean by feed them? Sorry I'm new to this, first year attempt!

Feeding them = fertilizing them.

1/2 cup water per day is definitely too much. Don't water again until the soil itself is dry, and not just the surface. Stick your finger down in it to see if it is moist. Or alternatively you can pick up a container and feel how heavy it is. A dry container will be much, much lighter than one that is moist.

Rodney

Seedlings that size even in much smaller containers don't need daily watering or even every other day watering so that is your primary problem. And once they develop their first true leaves they require a well-diluted supplemental fertilizer of some kind. Many discussions here about how and what to feed them.

But you have to quit drowning them first. ;-)

Dave

Thanks for the help! Much appreciated

In addition to the good advice above--did you by chance open that window on a nice day and expose the plants to direct sun? Because the white/light tan patches look a lot like sunburn.

No I haven't had that window open yet, but they are sitting in front of it all day, could that be an issue? Also, to update, some are starting to get black spots in the middle of the yellow areas. The smaller plants are dying while some are growing quite well. Does the yellow and black mean they're sick? I'll upload some pictures

If the window has stayed closed, then sunburn is very unlikely.

They look better in that pic.

The leaf problems are due to some sorta climate shock, watering well sun is beating on them causing sun scalding, cold nights, etc. They'll recover just fine. Water when dry, they appear to be doing pretty good.