Help with Pen tool!!

Thank you... this makes sense but the problem is i dont know how to adjust handles and change smooth to corner. Ive kind of taught my self how to use the pen tool but now im thinking its best i watch a proper tutorial. And shapebuilder too as that is so confusing to use 😕😕 I traced this swimming pool (attached) purely using pen tool and mirror transofrm but i think i could have possibly used shape builder for large parts.

Do you know of any good tutorials?

Thank you!

Daniel