Question

1. Slope = ½ and b = -3
I need two points

Answer 1

I assume you mean
y = 1/2 x - 3
So, just pick two values for x, say, 0 and 1, and figure what y is for each.

Answer 2

if you are following standard notation:
y = (1/2)x - 3

now pick an x, any x, (I would pick even x's to avoid fractions)

Come back with your two points so we can check them