With the way they structure seasons, any current spotlight challenges will expire once the season ends and a new set of spotlight challenges will be available.
You only need to complete one set for the achievement.
They can range from Triple Threat games to full 5 on 5 games.
Each game has a specific player/win condition (i.e., use Michael Jordan in your lineup and get 10 assists with a player in a game).
If you feel the challenges are too difficult, you can wait until a new set is out.