lower leaves yellow

Don't pull yellowing leaves in veg. Nitrogen is a mobile nutrient, so the plant is moving it from the older leave to the new ones because the soil is running low. If you remove them you are removing the little nitrogen the plant has in it that it can use immediately. Just up your nitrogen in feeding and it will be fine. Most of those lower yellow leaves will not recover, but leave them on until you have solved the N issue.

Under watered under nutrient…..

The picture is very unclear but it just seems like a N deficiency, easily fixable, just add more. No need to remove the leaves, the plant is visibly pulling the nutes from them because it needs it right now. Instead just check if there are ones that turned brown, remove them as to avoid possible rot/mold forming. You can also simply touch them or pull a bit, they should come right off without the need to pinch or rip if they are "dead". Your plant also seems quite droopy, not sure what caused this, would need more information on your feeding and watering schedule.