Step 1: Go to Posts > Add New to create a new post.
Step 2: Give your post a title and content in the text editor.
Step 3: Scroll down to the Page Options panel where you can control the way the post looks.
Step 4: On the right hand side you will see a Featured Image panel, click the Set featured image link to set an image for this post.
Step 5: After uploading or selecting your featured image click the Set featured image button in the image upload window.
Step 6: On the right hand you can assign your post to categories from the Categories panel e.g. “Blog”.