Thanks for your reply.
From the beginning of my hive journey, I've learned that every images collected from online should be credited properly. I don't see you mentioned pixabay or unsplash anywhere in your post.
and about the thumbnail.
I believe you collected the image from online and then used canva to add the letterings and the arrow and if that's true then you can't say you made it.
This is what I know and I may be wrong. If you know otherwise then you may enlighten me, I'll be happy for that.
Thank you for getting back to me! Pixabay and Unsplash both state on their websites that the images on there may be used without credit. However, if it makes the currators more comfortable then I am happy to start mentioning the use of their sites in future posts.
The thumbnail image was one of the default templates on Canva, I kept the default image and background including the arrow and I changed the lettering. If you look through the templates yourself you can see it, but I am also attaching a screenshot of what it looks like to me - I did not take the image from somewhere else and/or steal it.