the logic of the posted code is flawed, you set the turtle
object at the beginning and it appears (as it should). but then you use an endless loop that update
the object but there is nothing to update.
so the code after the loop is never executed -> no shape will appear
So doing the following will show the expected result, getting rid of the infinite loop:
import turtle
wn = turtle.Screen()
wn.title("Pong Game")
wn.bgcolor("black")
wn.setup(width=800,height=600)
wn.tracer(0)
# Paddle A
paddle_a = turtle.Turtle()
paddle_a.speed(0)
paddle_a.shape("square")
paddle_a.color("white")
paddle_a.shapesize(stretch_wid=5,stretch_len=1)
paddle_a.penup()
paddle_a.goto(-350,0)
wn.update()
solved Not importing shape in python