...your plants are in need of nitrogen. On every fertilizer, you'll see 3 numbers (10-5-5) or (N-P-K).....N= nitrogen (always the 1st #) P = phosphous (always the 2nd #) K= Potassium (always the 3rd #)
...you need some fertilizer with a high (N) during veg/grow, and fertilizer with a high (P) for flowering/bud/bloom...while giving (K) in low amounts and constantly.
Good organic fertilizers for newbies, IMO are bat guanos.