Liking Trek means being good at coming up with and or accepting established fan cannon explanations/excuses for why stuff happens, as often it makes infuriatingly little sense otherwise.
DS9 is the strongest of the older shows in my opinion and gives a really good grounding for the politics of the Federation and unfederated alien races involved (and for new trek shows like Disco and Lower Decks), while having enough plot and action to be interesting.
It still has a lot of bad acting and poor writing (especially in the first few seasons, ugh) and it's practically a radio play for seasons at a time though, so be warned.