So to get started I would get everyone a set and build together. I like Star Wars sets, my Wife is in to Harry Potter, my son likes both.
There isn't really a right or wrong way to Lego. I would setup a budget/limit though, otherwise you could spend quite a bit.
I collect Boba Fett minifigures so I usually focus on those sets and occasionally buying old ones to complete/keep my collection going.
The larger sets are pretty amazing. Most lego cities you see are mainly comprised of what they call Lego Modulars. https://brickset.com/sets/theme-Creator-Expert/subtheme-Modu...
These are some of the best builds, they retire though so I would buy the oldest one you can find new in box at retail price to start if you're interested in these, then buy the current retail ones oldest to newest, keeping watch for when they are retiring, usually Lego will mark them retiring soon.
Lego Architecture sets are really cool. My son collects those.
Collectible minifigures are fun they come out in packs a couple times per year, you'll get good at feeling the packs to figure out what they are.
Then there are MOCs (My Own Creations) these are custom builds that you make or you can get instructions or free build someone elses.
It's a pretty amazing hobby.
Check out Bricklink for parts (recently bought by lego).
Feel free to post questions here or msg me your email.
It's a fun hobby, lots of amazing custom builds out there.
Totally agree, there are so many ways to build and play. I know some people who are collectors, some who are remixers, some build from scratch. Some build big, some build small, etc. (Would also echo the budget comment ;) )
Some other resources I'd recommend: https://www.brothers-brick.com/ and the subreddit https://www.reddit.com/r/lego/ . There are also great forum communities out there for different sub-interests.
I highly recommend the Saturn V rocket. Lots of fun to build and it’s pretty impressive once done.