What was the problem or conflict of Diary of a Whimpy kid Dog Days?

Greg's dog gets him very mad, he loses to rowley in a game tournament because his hand gets mashed by a mallet(He scared Rowley). They go to the town pool, and Holly Hills is the life guard and he does everything he can to make her shift easier. Lastly his mom makes a photo album full of photos because she is sad that she didnt before