Try to break down the task:
On mobile, you want to make the paddle follow the finger left and right.
→ It should only happen when the device is a mobile device
→ Left and right is the X axis
→ The paddle can be positioned on the X axis
→ The cursor X axis position can be queried through expressions
Now try to think about what kind of actions, conditions and expression would be useful and necessary for this, search for them in the action/condition/expression selectors, and assemble them accordingly.
I’ll let you try to do that it by yourself, as spoon-feeding the solution wouldn’t help learn GDevelop as well. If you still do not find the solution, please tell so that I can show the solution.