When I was just learning how to play as a teenager...I use to go to a Par 3 course and play by myself all the time. I would go after school and get in 9 holes. I found it helped me develop a really good short game...as I could play the course with just 4 clubs....9 iron, PW, SW and my putter. My scores improved on the regular course I played the more I practiced at the Par 3 course. As I got better, then I would play 9 holes on the regular course I played, to practice my fairway woods and long irons, intentionally leaving myself 180 yards or more from the green. Once you start finding friends to play with, and are faced with a shot you have made practicing by yourself, you will have good memories of making the same type of shot and you'll be able to focus on hitting the shot you need to make without the negative thoughts.