Aim ball with mouse, add force holding mouse down

I've searched on here and on Google for some answers but I'm not really into coding so in a lot of cases it's like reading Chinese, especially if the problem is kind of the same, but not really.

Anyways, I'm trying to make a minigolf proof of concept kinda thing. My goal is to train my 3D modeling and scene creating skills so I needed something with simple mechanics to play with. Minigolf is aiming and adding force to a ball. I managed to get the ball rolling down the lane with a set force, but there's no aiming and there's no variable force.

What I need help with:

1 - Moving the mouse to aim where the ball will go

1b - Drawing a line that fades out at then end to show the direction of the ball

2 - Holding down the left mouse button to charge the shot

2b - Drawing a power meter to show hard you are going to shoot

Down here you can see what I've created as a start. I've drawn the stuff that I need help with. In advance, from a 3D modeler to someone with knowledge about coding: thanks!