Dad liked Star Trek so I watched with him since I was 3 or 4 years old. I became a much bigger fan when I had a job with odd hours and watched DS9 reruns at night in the mid 90s.

My first introduction came from an episode of Reading Rainbow in which LeVar Burton takes the viewer on a behind-the-scenes look at how some of the props and special effects work on this other show he’s on called Star Trek: The Next Generation. I watched whatever the next episode was after that airing. According to IMDB, that episode aired August 15th, 1988, so it likely was a rerun from the 1987 season.

I actually don’t have a satisfactory answer to my own question.

Star Trek was a prominent part of the popular culture when I was a kid, so it was easy to have a basic knowledge of TOS without actually seeing it.

I think I probably saw Star Trek IV first, and the first episode I can clearly remember watching is “Unification II”, though I’m pretty certain I saw something before then.

My parents showed me the episodes of TNG that didn’t have any content they objected to and taught a moral lesson. Most episodes have a moral lesson so I got to watch most of TNG before I was an adult. I have since then watched most of the available Star Trek content out there outside of anything TOS. I may find it in me to watch TOS but I’ve been hesitant to go back before TNG because that show is special to me.

Trying to get out of doing homework, me and my siblings would join my mom to watch her Star Trek - she didn’t object. Most times, it was TNG, with the occasional bit of DS9 or VOY.

She had actually gotten into TNG as a teenager - she’d read a few novels from her local library and kind of liked it. She then found Wil Wheaton hot enough to actually watch the show. (She may have watched a bit before that, but that’s my recollection, at least).