At the beginning of each hole you will be able to see what the par is. By the end of the course, you will need to have a total score of -1 or lower. The best tip I have for you is just practice. You may not get this on the first try if you aren't used to golfing games.
The computer will usually pick your club and aim relatively well, but you will most likely need to adjust things at least a bit, so don't be afraid to move around or even change the club of choice. It is very important to keep your ball in-bounds. Note that the spot in the center of the aiming circle is where your ball will go if aimed perfectly. The ball will then roll as far as the edges of that circle. The ball is also pushed around by the wind, so be sure to check the direction and magnitude before each shot. Use the spin feature (right analog stick) to add more precision to your shot. Use the power shot feature (B button) to add extra distance to your shot, but be careful that you may lose accuracy. Bullet time can be used to chip in the ball sometimes, but it will still take some good aiming. Note that using bullet time cannot make sharp turns with the ball and always try to keep some for when it comes time to putting.