The soil is way too hot for the plants. Since they are so small, I would recommend transplanting them into something less nutrient filled. Chances are that the potting soil already had nutes in it, and combined with whatever you added, was too much for the plants. They will probably survive if you transplant them soon, but will take a while to recover. The damaged leaves won't recover but newer growth should be OK if you act quickly. Plants need very little nutrients, but if you listen to how everyone pours stuff into their plants without knowing what is already in the mix, you would be surprised that folks have the success that they do.
Do yourself a favor and go easy on the nutes until you get a better feel for feeding them. I have seen too many grows end in disaster because of someone's recommendations to feed the shit out of their plants. Removing nutrients from a growing medium is 1000% harder than adding them, and the results are usually not good once they are overfed.
