Syntax: This is a complex sentence structure. 'I know a place' is the main clause, followed by a relative clause introduced by 'where' ('where the grass is really greener'). 'Warm, wet and wild' is a series of adjectives (a triad) describing the place in a fragment sentence for poetic effect. 'There must be something in the water' is an idiomatic independent clause expressing a hypothesis.
Morphology: 'Greener' is the comparative form of the adjective 'green'. 'Sippin'' is a contracted, informal form of the present participle 'sipping', showing casual speech. 'Undone' is a past participle used as an adjective meaning 'relaxed' or 'not fastened'.

Syntax: 'The boys break their necks' is a hyperbolic main clause. 'Tryna creep a little sneak peek' is an informal, reduced purpose clause. 'Tryna' is a contraction of 'trying to'. 'Creep a sneak peek' is a verb+object collocation where 'creep' means to obtain stealthily.
Morphology: 'Break' is in the simple present tense, used for a general, habitual truth. 'Tryna' is a phonological contraction common in informal spoken English, representing 'trying to'. 'Sneak peek' is a compound noun.

Syntax: 'We're unforgettable' and 'We're undeniable' use the linking verb 'be' + adjective predicate structure to state a quality. 'Daisy Dukes, bikinis on top' is a noun phrase list describing clothing. 'Sun-kissed skin so hot we'll melt your popsicle' uses the adjective 'hot' in a comparative sense, followed by a result clause introduced by 'so... that' (with 'that' omitted informally).
Morphology: 'Unforgettable' and 'undeniable' are adjectives with the negative prefix 'un-'. 'Sun-kissed' is a compound adjective. 'We'll' is the contraction of 'we will', future tense.

Syntax: 'Fine, fresh, fierce' is another series of adjectives (a triad). 'We got it on lock' is an idiomatic clause (SVO). 'West Coast represent' is an imperative sentence fragment urging representation. 'Now put your hands up' is a clear imperative command.
Morphology: 'Got' is the simple past/past participle of 'get', used here in a present perfect sense colloquially ('have got'). 'Represent' is used as a verb in its base form for the imperative.

Syntax: 'Toned, tan, fit and ready' is a list of four adjectives. 'Turn it up 'cause it's gettin' heavy' is a compound sentence with an imperative and a reason clause introduced by the contraction ''cause' (because). 'These are the girls I love the most' uses a demonstrative pronoun ('These') as the subject, with a relative clause ('I love the most') modifying 'girls'.
Morphology: 'Toned' and 'tan' are adjectives derived from past participles. 'Gettin'' is a contracted, informal form of the present participle 'getting'. 'Heavy' is an adjective used metaphorically. 'Most' is the superlative form of 'much'.