If you want to get an entire set of clubs then there are some crucial factors to be aware of before purchasing.
Quality - It is definitely worth going for brands that are well-respected in the game of golf because the products will have been made properly and would've been designed to perform properly.
Forgiveness - The most common problem for beginner and junior players is mishit shots which limits distance and hinders accuracy. Beginner and junior golf clubs are designed to have larger heads and sweet spots, and therefore more forgiveness to help players still make solid contact with the golf ball.
Budget - Obviously there are different sets at different price points so it is worth thinking about whether you want to spend more or less here.