Its easy buddy,
the first thing you need to do is of course, start a workout routine for your whole body associated with mainly weight resistance training. You should try to keep your cardiovascular at a minimum, though as a basketball player that you are, you tend to run alot.
But with all the workout that you may or will do, you need to of course feed your body with valuable nutrients to create growth. mainly a surplus of protein/carbs/ and of course fat (healthy, monosats, polysats, minimal saturated)
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figure out what your daily caloric needs are to sustain your current weight, to get big and bulk up. would require you to eat a "surplus of 500-1000 calories" Of course these meals will also be split throughout the day, 4,5,or 6 meals a day, depending on you.