Trying to load install for first time using macos Mojave

Got through setting is all up and through the disk utility thing where you name it MacintoshHD but when I go back, it says Install macOS instead of reinstall. plz help :,(

https://preview.redd.it/xn3vkovhlxo41.png?width=1190&format=png&auto=webp&s=874124095ccb3773f60096e8cc20a0904f1ae591