There's several things to take into account.
1. You need to know if the ball is close enough to be kicked
2. Is it in a position to be kicked? E.g not behind the player
3. Which way is the ball to travel?
4. What variations are there? Speed? Curve etc.?
There's different ways of doing this:
The simplest way would be to have an invisible actor that sits in front of the player and moves as the player moves. This actor doesn't need a collision shape.
Then check if the ball is within a certain distance of the invisible actor.
If it is, when the player kicks the ball, get the current direction of the player and use that to send the ball in the right direction.
You can check the distance using Pythagorean theorem: If sqrt (( x of obj1 - x of obj2 )^2 + ( y of obj1 - y of obj2 )^2 ) < distance
There's also the Easy Math extension with a block to calculate distance.
As for number 4, that's more complex. Do you need any variations?