Whooshing sound
What's the deal with the whooshing sound when I try to boot up my MacBook Pro? I'm trying to install a new mac OS but I can't because I either get the message, "An internet connection is required to install mc OS" and if I try to boot up my laptop I just get a whooshing sound and it keeps cycling back to start up. Can't go any farther in the process. Stuck.
MacBook Air 13″, macOS 10.15