if some one could please advice about is that curl...

Too early for the nitrogen

Man, stop feeding !!! Never use coco and soil mix, choose what way you want to go and do it, mixing two different styles only brings problems. You are burning them, i did diaries with 0 food in soil pots, from seed to harvest nothing added. growdiaries.com/diaries/164016-grow-journal-by-asnoriu Now with curl in all sides, not only overfeeding makes leaf twist, by look i think you have wind damage too. Any direct constant wind ? Oscillating fans, with no wind intervals, thats what weed loves. Why you have those holes, you overwatered pot at begining and wanted for it to dry out quicker ? Overwatering makes leaves twist too, in diary i shared with you you can see it perfect with my plants , sometimes it happens, that issue they will overgrow. But not feeding, slow down !!! Good Luck !

Nothing to worry about, quite often the first (few) sets of leaves can be a bit strange for no reason at all.......the plant is just still trying to figure out "what all this growing thing" is about.

those fist serated blades can be a bit odd.. new grwoth is not curling so probably okay. Watering habits look off though. See hint of imbalance in leaves already. Could be related to the likely bad watering habits. Water entire substrate without leaving any dry zones. Wait for top 1" to dry. Repeat. Don't deviate. A little runoff is fine with soil to ensure the whole thing got wet. How frequently you add fertiization depends on the concnetration of it - like riding a bike you have to learn how to balance it out with some traial and error about how often, how much, and what ratios. If you experience any buildup of minerals, give more irrigations of water only before resuming fertilization.