If you don’t have your own GA4 data in BigQuery, you can query the GA4 sample data available via BigQuery Public datasets.
The sample data is derived from Google Merchandise Store (an ecommerce website owned by Google) and Google ‘Flood-it’ mobile app (a mobile gaming app from Google).
How to access GA4 sample data in BigQuery?
Follow the steps below to access and query the GA4 sample dataset in BigQuery:
Step-1: Create a new Google Cloud Platform account. If you already have the account, then log in.
Step-2: Create a new BigQuery project. If you already have a BigQuery project, then navigate to it.