see aesparza, basically you need to do the first grow to truly see how the plant grows and u will realiuze its very simple and basic no matter what you want to do....dont get confused with all these fancy names...when someone "tops" a plant all that means is cutting off the top meat of the plant and the natural healing process of the plant is to turn into 2 main stems, so on and so forth.
and when someone says LST its even easier, all LST means is bend the plant down and make it go what direction you want it to...bend it over and think of anything to hold it bent over...maybe a screw in the outside rim of the pot and there u have it...put a loose string knot around where u want it to start bending over and pull the whole stalk to the side and tie the string to the screw but not too taut, just gently constant tugging to keep it from standing upright again...
and a scrog screen is a screen that has squares in it that you put over your plant...anytime new growth tries to grow through the square you bend it back under, big deal...lol
they are all simple basic ideas that work great...
i would definitely keep it simple though...focus more on it stayinbg alive then by not overwatering or over nuting...air flow, proper temp/humidity...dont bite off more than you can chew on your first grow and trying to get a pound off that plant,lol...
and you should def. get a different light, if your already using 400 watts, get a 400 watt metal halide and hps light, if thats your plant at 4 weeks from clone your not gonna believe this is one of mine under a 400 watt Metal halide at only 14 days