follow these steps to connect to Salesforce:
1. Connect to New Data source.
2. Click on More and select Salesforce.
3. Click on sign in using username and password.
4. Enter the username and password and click Ok.
5. You can now see your files that are available from Salesforce to make visualizations.
6. Select the file (data source) and click on sheet.
Hope this helps you.
If you need to know more about Salesforce, It's recommended to join Salesforce Admin Certification course.