i do believe you have a magnesium deffency. any more info will help, what stage veg or flower? what nutes? indoor outdoor? lights temps? any helpful info will get more answers but i believe its mag deffency. your probably starting to flower and it needs more p..
Both are seperate issues Green leaf (on the right) is getting munched. Get some neem, spinosad(Capt.Jacks Dead bug), and safers( go light on the safers especially with neem, together in large doses closes stoma, and suffocates leaves to death) Yellowing could come from several issues, more info needed. Location outside( what is it around, any spruce or pines close, etc) What have you done( basic prep, ferts, admentments used, etc..) Temps, watering, etc. The more info(or Pics) we get the better we can help.