First, you need a Google project with BigQuery and Billing enabled.
See this Google setup guide for how to set up the project and enable BigQuery as well as how to share it to Google Data Studio and this article for how to set up billing.
1. Create a BigQuery Share
Create a new BigQuery Share on the Data Warehouse page and take these steps while setting it up:
Set 'table options' to "single table" (default)
Select the fields you want
Select the date range you want
Click "Edit field format" and edit the names and types of the fields the way you want them in Data Studio (optional)
2. Connect your BigQuery table to Data Studio
Create a new report in Data Studio or click "Add data" on an existing report. Then select the BigQuery connector and then select the Google project, dataset and table you shared data to in step 1.
3. Start building your dashboard
The data is now available in Data Studio, you now start building your dashboard! 🎉