It doesn't make a difference if you are just starting out in pool. Both can be fun and competitive, but 9 ball offers more chances to win. The best way to decide between them is to look at your individual style and your gaming skills.
Playing 8 ball is great for beginners or those who just want to have fun. You will have many more opportunities to make shots, and the game is easier than 9ball. The game is more difficult than any you have ever played. You need to be familiar with all the rules, such as the rule to pocket balls in numerical order, and you will need to be able to shoot balls in a particular order.
The 8 ball is a tricky one. You need to know when it's safe to make a run for it, when you need to keep it in your pocket and when you should play safe. To make a run out you'll need to first pocket the balls on your team, and then take the 8 ball. Depending on the tournament you are participating in, you may be required to make a certain number of pocket shots before you can run out. However, you should be able hit the 8 ball in as little as one shot.
There are many similarities to the 8 ball as well as the 9 ball. You can either use a triangle to direct the balls to the correct spot or play with slop. You cannot pocket any 9-ball ball. You can only make a few shots on a 9 ball. The "Golden Break" is one shot that will allow you to win the game regardless of how many balls you have previously played.
After your break, you can make the Golden Break. The shot is a way to win the game. You will need to feel the cue ball well or else you might be surprised. You will struggle to make the 8 ball if you don't have it. The rules for 8 Ball will vary slightly, but you should be very precise with your shots. It is not as forgiving and easy as it may sound.
The main difference is that 8 and 9 balls are slightly more challenging to learn. However, it's more difficult to master. In fact, there are many different national bodies that govern the rules of 8 ball, and if you are unfamiliar with them, you will have to read up on them before playing. Remember that rules for 8 ball are different from 9 ball.