plant flowering need serious help

well i have no idea what to do now ive tried reading things but still dont understand i think my plant is starting to preflower and i wasnt to do the best i can for the plant what do i do/ nutrients and when its considered flowering what do i do as in nutrients and so forth

i will +rep anyone that helps i want to do this right the first time
here is my plant now

heres a link with pics from 3 days ago
https://www.rollitup.org/general-marijuana-growing/114765-male-female.html

well as far as nutes go u should have started them on nutes back when they were 3-4 inches tall introducing small amouts ofcorse. good nutes for a begginer?i would recommend genral hydroponics flora series nutreints as they are realy easy to mix three part system comes with a chart on the bottles of how much to add CANT FUCK IT UP basicly.those nutes work awsome to by the way u can use them from beggining to end then once u get the hang of it u can start using additves and such.As far as preflower u dont need preflowers to bud when the plant has reached a desired hight u can change to light to 12/12 and the plant will start budding totaly skiping the preflower stage as far as i know this does not hurt the plant in any way shape or form as i do it this way also i think the preflower method is use for people who grow out side being that they cant adjust the day light scedule.keep in mind if u start budding ur plant at 2 feet expect a 3 1/2 -4 foot plant most people dont think of it but u will quickly out grow ur space and moving them when the flowering is not an option at this point as u will stress them out to much witch will result in DEATH or very small yuild.