To upload from your local drive, start with the following code:
from google.colab import files
uploaded = files.upload()
It will prompt you to select a file. Click on “Choose Files” then select and upload the file. Wait for the file to be 100% uploaded. You should see the name of the file once Colab has uploaded it.
Finally, type in the following code to import it into a dataframe (make sure the filename matches the name of the uploaded file).
import io
df2 = pd.read_csv(io.BytesIO(uploaded['Filename.csv']))
Dataset is now stored in a Pandas Dataframe
Source: Get Started: 3 Ways to Load CSV files into Colab – Towards Data Science