Help Random Falling Objects

Hello I am having trouble creating random falling objects. For example, I would like an ball to fall from the top of the screen (outside frame). I would like this ball to be spawned at random intervals, but I would also like the multiple balls of the same image to fall at the same time (the character needs to avoid getting hit by these balls so multiple falling at the same time will be necessary) on the screen (without overlapping of images). I am new to clickteam and finished the tutorials, so please explain everything carefully. If possible I would like to make a power up fall once in a while, but not as often as the ball. I am sorry if Im a bit vague, but any help right now is better than nothing.

Thanks for the help. One problem I am noticing is that the when the objects drop and fall out of the bottom screen it would spawn a new object. The randomn x position worked, so thank you for that! However, I don't want the game object to only spawn when it falls out of the screen. I would like multiple balls falling at different times. Essentially, I don't want the the ball to spawn only because the one before it went out of screen. I want numerous balls dropping from the top. The object of the game is to avoid the balls and it makes it very simple to have one drop at a time. I have also been noticing that the powerup and the balls have been overlapping. Please help me on that as well.