Calculate the pH of 0.010 M HNO₃ solution

Here, we are dealing with an acid, namely nitric acid
This means the H⁺ concentration is 0.010 M

Whenever you see a lowercase p, it means 'take the negative log of'
pH means take the negative log of [H⁺], the proton concentration

So let's do just that

pH = -log [H⁺]
pH = -log [0.010]
pH = -(-2)
pH = 2

The pH of 0.010 M nitric acid solution is 2