Lol it's okay, I've been there too.
Probability is the chance that an event will occur. In your specific case, probability is the event that the spinner lands on blue. The probability of that happening would be 2 / 8, because there are two blue pieces out of the eight that are there.
When a question refers to it not being a certain color, say blue, the probability would be 6 / 8 because that's the rest of the fraction.
Also, you can re-write these fractions as percents and decimals if you know enough about it. 2 / 8 = 25% = 0.25
Hope this helps!