To add a new blog post in Squarespace, you'll need to follow these steps:

• Log in to your Squarespace account.

• Click on the "Pages" button on the left-hand sidebar of the dashboard.

• Select the blog page where you want to add the new post.

• Click on the "+" button at the top of the page.

• Select "Blog Post" from the dropdown menu.

• Add a title and content to the blog post.

• Add any media or formatting you wish, such as images or links.

• Add tags and categories to help organize your post.

• Preview your post to make sure everything looks good.

• Click "Save" to publish your post.

You can also schedule your post to publish later, or you can save it as a draft to come back to later.