First time!
Roughly so far looking at hitting up SFO, LAS and a circuit out through Rachel to indulge my nerdy side with a is it to the little A'le'inn
Then looking to spend most of our time on the east coast, wanting to see Miami, visit some friends in Asheville NC, New York and Boston.
We have 5 1/2 weeks
Out of that list, I can comment on SFO, LAS & NYC. Allow at least 3 full days for a taste or longer if you can.
SFO - Love it! I'd start with a double decker bus or Aqua Duck tour to get your bearings. You'll probably spend most of your time at Fisherman's Wharf, downtown & the Castro. Get a Muni passport (1, 3 or 7 days) & you'll have unlimited public transport with Muni & cable cars. Especially important considering a cable car fare is $6 flat fare. You must do the cable car & the vintage streetcars.
Vegas - Bet with your head but not over it. Even if you aren't a betting man, go for a walk through a couple of casinos. My favourite to walk through is New York New York (mainly for the shops).
Walk the strip by day & night. Totally different vibe. Also check out downtown & the Fremont St Experience by day & night & the nearby container park.
There are courtesy shuttles from the various casinos that will take you to other casino, especially if they aren't on the strip. My example was Rio (off the strip) to Harrahs (on the strip).
Many of the things you will need in a casino are there - it's designed so you don't want to leave, especially when it is hot. Some casinos have virtual alliances & some are basically phyiscally joined.
The strip gets busy so you may not want to get a cab. The regular buses are totally fine & cheaper.
NYC - Love NYC also. You'll probably want to be in the thick of the action in Manhatten. Subways & buses are perfectly fine. Once again, a flat fare applies so get a daily or weekly Travelcard.
Remember airline style security applies at the Empire State Building & to the Statue of Liberty. If you don't want to be on the island in front of the statue but want to see it, a good option is the free Staten Island ferry. Broadway & Times Square is where a lot of the action is. You'll probably want to go to Ground Zero & the 9/11 Memorial site.
General tips:
Allow a day or two after arrival if you decide to hire a car.
Lots of people will expect tips - much beyond the usual ones you might expect. Tour guides, shuttle van drivers, bar staff, housekeeping & a lot more. Even if it isn't stated, there will often be a sign or a tip jar. Some bars have a one drink minimum if there's live music.
Don't expect free wifi in hotels. I've got a $70/month prepaid SIM with T Mobile aimed at Internationals for unlimited data, US calls/text.
Don't give to homeless people/panhandlers. You'll find so many of them & once you give to one, others will swarm you. A common scam is people will hand you a CD. You think it's free. It isn't.
Try & blend in with the locals.
US banknotes look the same if you have a boylook. They aren't different colours like ours.
Take at least one powerboard & an extension cord. Plug all your chargers etc into that & plug the cord from the powerboard into an adaptor then the adadptor into the wall.
And finally, Americans generally love Australians but some aren't used to our accent. If you use Australianisms that aren't inspired by Crocodile Dundee or Steve Irwin, they'll have no idea.