Two sub domains

Hi Folks. I hope someone can shed a little light here for me. I already had a site on the domain and my client asked me to create a wordpress site for him. WE wanted to create the new site without disturbing the original until we were ready. I am relatively new to wordpress and followed instructions to create the new site. The domain name is https://www.ilase.co.uk. I created a subdomain called blog. Inside blog, I created another subdomain called iLase_wp.
I then uploaded / installed wordpress in the iLase_wp folder.
I like the idea of keeping the wordpress files in a subfolder, but should I try and get it all up a level? If so, how can I do this without causing problems?
If I was to simply delete everything and start again, would the database still be trying to find the second subfolder?
Hope this makes sense