lil' - colloquial form of "little"
wit'- short form of the word "with"
NBA- National Basketball Association
out back- in this context "out back" means "behind the house"
take a dip- take a swim, go swimming (usually implies for a short period of time)
gotta- in this context "gotta" means "got a" or "to have a"
shoe closet- a closet just for shoes
kicks- slang for "shoes"
to be big- in this context this phrase can mean "to be as big (physically)" or "to be famous or well known"
from downtown- a phrase used in basketball meaning "from behind the 3-point line"
condo complex- a group of condominiums (similar to apartments)
'cause- short form of "because"
word- in this context "word" is slang for "yes" or "yeah" (usually to agree with someone or emphasize something)