I’ve collected and played the Star Trek: Customizable Card Game since 1994, or possibly 1995. The first cards I got had the 1994 copyright date. Initially, the company that made it, Decipher, branded it as The Next Generation, as they only had the rights to that show at the time. A bit later on, they got the rights to the other TV shows, and the movies.
Adding lots of cards over a long time does tend to make a game convoluted. Some rules changed from the original rulebook, and a long Glossary came into being to help clarify what some cards do, and/or their interactions with other cards. After several years, the game got a bit complicated even for Decipher, and they started afresh with a Second Edition (2e). They made some cards that were backwards-compatible, which were initially well-screened, but then later on some crazy ones slipped through, which were either too powerful, or did absolutely nothing, in 1e.
Decipher ran into financial trouble, and lost their licenses (they had a Star Wars game or two, and a Lord Of the Rings game). Decipher passed on the use of the 1e and 2e mechanics to a players’ group called The Continuing Committee. I think they did something similar with the Star Wars game, but I never really got into that.
The CC started with an emphasis on 2e, but slowly worked their way into 1e, starting with making printable versions of useful cards, before branching out into making new cards.
After a few sets, the CC made a big splash with a set called The Next Generation. One of the problems they had encountered was that the power level of the game had increased over the years, but returning players were much more likely to have cards from the first three sets (Premiere, Alternate Universe, and Q-Continuum, often abbreviated to PAQ), which is really a very different game to that of any stage after, even beginning with the following set, First Contact.
They actually did a very good job with different ways of making old cards useful (and not just as backing for new cards). They also made The Next Generation a starting point for a new format, Block, which is an excellent environment for introducing new players. There’s a limited card pool, which makes it easier to learn, then you can throw in more cards later.
The first three Block sets concentrated on The Next Generation, establishing as a powerful faction in the game, despite their below-average general card power.
In the game, Voyager cards were distinct by being generally stuck in the Delta Quadrant (and being somewhat ahead of the power curve of anyone else), and Original Series, Original Series movies, and Enterprise were distinct by being from different time periods. TNG and DS9 weren’t so distinct.
The second three Block sets concentrated on Deep Space Nine. Game mechanics were given to TNG and DS9, in the first 6 Block sets, to make them playable as distinct factions (of course, you have the ability to not use them, and have a deck crossing over as many shows as you like).
It’s release day for the first of the next group of Block sets. This group focuses on the Mirror Universe. This first set, Crossover, concentrates on its appearances in DS9. There are 5 DS9 episodes featuring the Mirror Universe, and the two factions (the Klingon-Cardassian Alliance and the Terran Rebellion) are already represented in the game (the Terran faction usually mixed with the Terran Empire from the TOS episode Mirror, Mirror). This set capitalises on the DS9-only mechanic (so the Terrans don’t get too crazy good), and even gives each faction multiple ways to play (basically with or without Mirror Terok Nor).
The next set is intended to focus on TOS, and the third set in the block is intended to feature the Mirror Universe as it featured in Enterprise. This last is not distinct in the game yet, though there are some Backwards-Compatible cards from those episodes.
If you’re interested in picking up a somewhat intricate game, with many possible interactions, check out this unofficial rulebook (on which is based the forthcoming official rulebook).
If you’re still interested after that, check out this page for any PDF that has “starter” as part of its name. If you find someone to play it with, it’s probably best to play two starters from the same block (they’re colour-coded). And you can browse and post on the forums, particularly the Gameplay (1e) board, if you have questions or need help. The people on there are happy to help. And sometimes even experienced players have questions about old cards, so don’t worry about asking questions.