Understanding a dataset (prior to applying ML models) with no metadata given
The aim is to predict pm2.5 ( target variable ).

Step 1: Data Cleaning. Remove unwanted features and fill the missing values.

Step 2: To learn about the features, perform data visualization. You can plot a linear plot with TEMP and pm2.5 and see how it varies with change in temp.

Step 3: The next step is to find the relationship between features. Some features are not needed for prediction. Remove those features. 

Step 4: Apply a suitable machine learning technique and predict.