Social sharing buttons
To use sharing buttons in Journal you can work with any 3rd party service such as AddThis or ShareThis.
Once you create an account with a service like that, you will be able to activate the buttons you want on their website. A code will then be generated which you can copy and paste into Journal, in a Blocks module found in Journal > Modules > Blocks.
If you imported any of our demos, you can already see such a module created in Journal > Modules > Blocks > Share Plugin... You can use the same or just paste your personalized sharing code there.
With the Blocks module created, you can add it inside the product page via Journal > Product Extras > Extra Modules, or any other page via the layout builder in Journal > Layouts > ...