new to this, need help plz!

so i germinated my seed and planted it. its been about 2-3 weeks and one of the leaves are light yellow/whittish on the tip while the original two leaves that dont look like marijuana leaves are dying. i'm just using regular organic potting soil and using a flourescent bulb for now watering the plant ever 1-3 days. what am i doing wrong? i think im gonna start switchin to MH and i also have some nutes laying around thats 15-15-18. just dosed it with nutes today but very very diluted. any tips

You could be watering too often, which would make your roots not grow, which would make your plant not grow. How tall is it? Pics would be key.