I have a 13yo DS who plays competitive soccer, and has been playing since he was 3. The point of not keeping score is so that young kids focus on learning the fundamentals of the game, and not just on scoring. (And yes, the kids do all know the score but the coaches' focus is different and it is not just about winning). At the preschool and early elementary ages, it is much better to learn to pass the ball to a teammate than it is to boot the ball into the goal.
If you watch preschool soccer games in US, it is usually what I call "mob ball". All of the kids move in a pack up and down the field with the ball in the middle of the herd of kids. The biggest, fastest kid almost always kicks the ball towards the goal as hard as they can, and everyone else chases after the ball. So, to the OP, if your kid is going to be the fastest and biggest on the team, great. She will get a lot of touches. Otherwise, it's a lot of running and not much in terms of soccer skills.
DS's soccer program doesn't play competitive soccer games until the kids are 8 years old (and they start them at 3). Until then, it is all skills training and small sided (2-4 kids on each side) scrimmages.
My DSs played a tournament and went to soccer camp in the UK last summer. They were amazed by the skills of the 5 and 6 year olds. The European kids could pass and understand field strategy far better than any American kids.