Fully understanding bitcoin transcation verifying and secp256k1
G is a point on the curve, but multiplication on elliptic curves is not the same as just multiplying the x and y value by the number.
Have a look here https://en.m.wikipedia.org/wiki/Elliptic_curve_point_multiplication to see how you multiply a Point (G) with a natural number.
Because the elliptic curve, you are talking about, is not over the real numbers, but over a residual field (natural numbers mod N), the division is just another way to write the multiplication by the inverse (mod N) https://en.m.wikipedia.org/wiki/Modular_multiplicative_inverse