Yellow spots on the first leaves

Oh, little ones such as this often will exhibit strange markings/colors/shapes etc... and I wouldn't worry too much about their color. What I WOULD worry about, tbh, is that you seem to be watering a little too much although you say you're only spraying her - so maybe I'm wrong. Make sure the water you're providing is pH'd between 6.0 and 6.5 and that you allow the soil to dry out completely before watering her again. I would also tell you to take a tissue after every spraying and soak up any water that remains on the leaves... droplets magnify the light and can burn the leaves (which hasn't happened here!). I see nothing to worry about particularly.... give it another week and reassess but seriously, there's nothing that concerns me! Good luck!

and try not to flood, water every 2 days, little by little and happiness will come to you)👏

Greetings! In my opinion, the sheet is oversaturated with light. Try to reduce the amount of light supplied. Raise the lamps higher. Try it and see the change the next day. And everything looks good! Good luck +)))🙌