Answer:
The rate of change is 2.
The initial value is 3.
Explanation:
The rate of change is the slope of the line, which you can calculate with the following formula:

Then:

Therefore, the rate of change is 2
The initial value is the value of y obtained when x=0.
As you can see in the given points, when x=0 the value of y is 3.
Therefore the initial value is 3.