Start ... At The Beginning
Some people hit a major hurdle before they even start a painting by not knowing exactly where to start.
With acrylics, I start with the darks, and move towards the lights. I find this the easiest approach.
Acrylics are opaque and can be very forgiving. Anything you do can be painted over at a later time so there are “no worries”.
Darks give perspective to the painting and an illusion of depth with shadows.
Then I can finish with the yellows and whites to make the object shine.
I really recommend taking the time to understand the lights and darks and build the painting up off the canvas.