Advice for traveling within the US?

I (20M) and my girlfriend (20F) want to start traveling. my 21st is in a few weeks which i know is going to help. So will hers be by the time we take our first trip most likely.

We are from the southeast of the US. Neither of us have really been out of the south, at all. I have been as far as the keys, and dallas (I was not in charge). No farther north than NC. We like to take day trips. Do that once every month or two. First trip I/we ever took where I was in charge was new year this year we went to hilton head and got an airbnb for the weekend.

But I wanna start taking big trips. I have never flown. I also am not ready financially for this right now (obviously just wanna plan for now), but would like to be ready to take my first big trip within 6 ish months. My biggest places on my bucket list are New england, Pacific northwest, and California. More specifically:

- Boston + cape cod/nantucket/marthas vineyard in the summer, Acadia national park, portland maine, and driving through the region in the fall. Also wanna try lobster rolls

- Portland/Seattle, cannon beach, oregon/washington coast + nature, maybe olympic national park (and other good nature spots out there) Also wanna try their coffee.

- orange county and san diego (yes san diego and not LA with orange county, I am not necessarily against LA, but SD is more my style) Also wanna try their mexican food.

- Sacramento, lake tahoe, and yosemite.

Things that are important in helping choose a place include cool swimming water, cleanliness, friendly people or at least not rude, good food/coffee/chill bar scene, populated but not overcrowded, mix of nature/coast/city/crazy landscapes we’ve never seen before. etc. Also, my girlfriend wants to do these things too but isn’t nearly as picky as I am and trusts me to plan as long as we discuss and agree on what we do.

Any tips, ideas, places I didn’t list I should add, etc all would be good. My budget I am thinking might be 2.5k low end to 3.5k high end, stay maybe a week ish? Not sure, open to suggestions these aren’t firm. Dates maybe sometime between august and october, but again nothing set in stone. Also - I would like to travel outside the US but want to get used to at least my country first before going abroad.