Go in your WordPress Dashboard under “Appearance-> Customize-> Site Identity“. You’ll find a box where you can upload a logo for your website:
You can choose to show only the logo (recommended), or the logo with the “Site title” and “Tagline“.
Also, from the same panel, you can also choose to upload the favicon to your website.
Use different logo in individual pages/posts with Attesa Extra plugin
If you want to use a different logo on a particular page or post, you can do it with free Attesa Extra plugin.
Edit or create a new page, under the content box you will find a box called “Attesa Extra Theme Options”, go to the “Header Settings” tab and activate it.
You’ll find the option to upload a custom logo that will be visible only on the desired page.