More on the startup states:
∙ [https://support.apple.com/en-us/HT204156|If your Mac doesn't start up all the way]
∙ [https://support.apple.com/en-us/HT207019|If your Mac starts up to an Apple logo or progress bar]
To get to Disk Utility via Internet Recovery:
∙ [https://support.apple.com/en-us/HT201255|Mac startup key combinations]
∙ [https://support.apple.com/en-us/HT201314|About macOS Recovery on Intel-based Mac computers]