Before showcasing your awesome data science project to Kaggle, please make sure that the dataset is successfully loaded on Kaggle Notebook.
You have two options:
The first one would be selecting existed dataset or uploading your own dataset. ( File-> Add or upload data)
and then use the following code to figure where your dataset is
for dirname, _, filenames in os.walk('/kaggle/input'):
for filename in filenames:
df = pd.read_csv("/kaggle/input/dataset/dataset.csv")