Importing terrain not rendering properly

Hello, I am very new to unity and i'm learning about terrains and the book i'm reading asks me to import this specific landscape which is suppose to be some mountains, but this keeps coming up instead

I thought that it could have been the file itself so i downloaded other files from the internet only to result in the same issue. There is also something in the bottom right corner of the window that just says "5/11 Clustering | 1 jobs".

Let me know if anyone finds the issue hope its not a Mesh-up on my part! Thank you!