You can upload a logo using native Theme Customizer.
- Navigate to Appearance > Customize from your WordPress dashboard.
- Select Side Identity panel and click on Select Logo button.
- Media uploader pops up and you can see Suggested image dimensions.
- Upload your logo to the Media Library and select it (optionally, you can also crop the image to best fit the suggested image dimension).
- Click on Save & Publish button to save the logo.
Note: Please note that you may need to toggle Display Site Title and Tagline option in Site Identity panel inorder to hide Site title and site description.