Changing WordPress Address URL & Site Address URL

I created two websites. The first, https://trials2triumph.org (actual registered domain). The second, https://trials2triumph.org/blog. I know want to delete the first and change the second to: https://trials2triumph.org. Admittedly, I am a novice. I read your posting, I believe, on how to accomplish this but it is over my head. I don’t want to blow anything away. Is there a more simple method or can someone make this happen for me?