Start with the best episodic episodes of TNG and DS9. Most of us were introduced to Star Trek out of order, it isnt like modern TV. 90s TV and prior was focused on syndication.
My recommendations would be, TNG: Darmok, Tapestry, The Wounded, Inner Light, Cause and Effect, Lower Decks (The episode that inspired the show). For DS9: In The Pale Moonlight, Duet, Trials and Tribbleations, The Visitor (Rest in peace Tony Todd)
Syndication is also called reruns, when the show is rerun out of order on TV at a standard Timeslot. Like for me TNG was on every night at 7pm M-F. It was shown in random order as far as I know with I believe them skipping less popular episodes, I honestly never noticed if they did hits for a bit then did a rerun through it or what.
The first season of TNG is considered weak as a heads up, similar for DS9 though DS9 has some bangers in S1, TNG is mostly weak. That said if you like it, you’ll LOVE the rest.
SNW is fantastic and I really recommend it, it is certainly New Trek but it’s a MUCH better successor to the legacy than Discovery.