What’s wrong with my plant???

This is my first grow, I’ve done a lot of research but I’m still not really sure what the problem here is. The bottom leaves are a lighter green than the top, I’ve been using organic compost (coffee grounds, egg shells, etc) so it could possibly be nitrogen deficiency I guess. It’s also growing pretty slow, it sprouted about a month ago. It gets direct sunlight, and the temperatures are good here.
A cold front did come the other night (temperatures were in mid 40s) but I don’t think it effected the plant. I also had a spider mite infestation I used a water/alcohol mix solution and it seemed to get rid of them. I’m not sure what else information I should include. Thoughts?

Looks a little hungry to me I use hydro so not sure on organic nitrogen solutions i think you can use diluted urine haha but I’m sure there’s a less messy way

also make sure your medium is nice and airy and drains well

Nitrogen deficiency. I would amend the soil and check that your PH is within range.