Honestly I can understand that. It’s pretty overwhelming. Personally, if I were you, I would start with TNG and see how you like it. But… Give it two seasons. There’s some gold in the first season but at the same time from absolutely horrible shit, including one of only two episodes that I can’t rewatch when I burn through the series again.
But then it really takes off in season 2. Hell that one has measure of a man which is not only one of the best episodes of Star Trek it’s one of the best episodes of anything I’ve ever seen.