Your first mistake is "planning". Miami is not a place you should do any planning for.
If you are going to stay in Miami Beach, I can recommend the Riviere. It's not fancy - but I'm not one for fancy. Small courtyard hotel I think all suites at reasonable rates, in the middle of everything and walk to the beach. Good for any of family, business, or entertaining, so long as you are not trying to impress. Please plan showers for the extended wait for hot water.
Go gawk at the Versace House.
At least have a Cuban Coffee. David's closed on Collins apparently, I can't vouch for the new location on Alton Road.
Have your rental Lamborghini towed. There's little non-resident parking in Miami Beach.
Go get fleeced on Lincoln Road. Pick up an overpriced Britto. (But, actually, the nearby ArtCenter full of lesser known artists is quite worthwhile, and is partially subsidized for the artists in residence.) Pay special attention to anyone who greets you with "looking sharp, my friend!". Soak up the compliment. They have the scoop on the sharpest threads and best hotspots at the best prices.
Prepare to be turned away at clubs. If you aren't turned away, you went to the wrong place.
OK, you actually want to get in? Find 3 hot chicks to go with you, by offering to pay their way in and for their first drink. You will never see them again. But you will get in. Please just pay the cover, without realizing that they would get in free if you hadn't dug so far into your wallet. Note that they would not get in for free or at all if they were just a group of girls. That would make the whores. God forbid, the club should let in whores! Because they are with you - you handsome devil! - they are not whores. (They are whores!)
Prepare for no action. Because if you came with three hot chicks, you're gay.
Explore Coconut Grove and say "hi" to the peacocks Have your rental Lamborghini towed again for parking in the neighborhood. (There's little non-resident parking in Miami - too bad Car2Go went... they got a free pass).
I suspect if you don't want to go to an Aquarium, you also don't want to go to a museum. Go to the museum that belongs to Florida State University anyway. They have a great collection of Italian Fascist design. They have limited space, so the bulk may be in storage - they rotate it. But you can probably see some. This will bore you to tears. But when you go back to Pocatello, you can impress chicks with your esoteric knowledge of Italian Fascist design. It's sufficiently "edgy" to get you some second looks. People will forget - for a moment - that you are the Trust Fund baby of a wealthy potato farmer.
Some of this is genuine advice. Some is trolling. It's your job to figure it out.