Halo CE is a great start to a fantastic series that sets a lot of what made the series so great in motion, though not without a few flaws, specifically towards the end of the campaign. Assets begin to be reused much more than feels necessary, and a lot of outright backtracking happens, with not many physical changes except new enemies in old areas. But past that, the campaign is great, even for people who aren't used to the FPS genre, since the game has short, but in-depth enough tutorials on lower difficulties, while not nagging the player. The multiplayer in CE isn't as refined as later games, but the lack of online and focus on split-screen with how maps and modes were designed were mostly the cause of that. If you're going to play Halo for the story and campaigns (which honestly, you should), it's best to start with this one.