The 1st thing I would do is go to the website you bought your seeds from and look at the description, most banks give an estimated height and flowering time. For your info sativas generally grow tall and flower long were as indicas grow short - medium and have a shorter flowering period. Keep in mind that indica sativa cross will have different growing charecteristics. As far as light period goes, most plants do good with 18 on 6 off for veg and then 12/12 for flowering, but if your using auto flower seeds i wouldnt mix them with reg photoperiod seeds as autoflower plants need no change in light cycle, they start to flower right away also they will more thanlikely end up a lot shorter than your other plants. Search around in the growing section of this site, it contains a fountain of priceless information that will teach everything u need to know. I always search search search the topic u r interested in or try reading grow logs, nothing can compare to the experince that veteran growers share in there logs. Good luck and dont get discouraged, it is a learning experince and nothing is more valuable than that:smokin::smokin::smokin:

P.S if u know me push my digits my communication device was down