Hi Steve,
Thanks for reaching out and thanks for using BoldGrid Post and Page Builder for WordPress!
In order to save a block in Post and Page builder you just need to hover over the block you wish to save and click the “menu toggle” button to bring up the block options, select the “save block” Heart icon located in the lower right, choose a name for your block and click save.
After saving your block you can add it to any page by clicking the “Add Block” button at the top of the Editor and using the “Types” dropdown menu to select the saved block from your “Block Library”. You can use this article to help you get more familiar with adding and saving BoldGrid blocks.
I hope this helps. Please reach back out if you have any other questions for us.