You can use images from platforms like Adobe Stock, Unsplash, or Shutterstock. However, I would never recommend relying entirely on such copyright free images, as they are widely used by many people. When search crawlers find the same images across multiple sites, search engines may consider them as low value content, which can negatively impact your SEO.
To make these images unique, consider editing them to fit your specific needs. Tools like Canva, Illustrator, or Photoshop are great for customising images to align with your blog’s style and improve originality.