MacBook Pro stuck on opening screen

I Have an older MacBook Pro, it only works when plugged in now and says not charging so maybe the battery is old. But at least it worked. The last week or so it's been acting up on start up and last night we had a power outage and when the computer restarted I just get the apple logo, the program bar for a minute and then just a spinning wheel. Tried safe mode and nothing. can pull up disk utility etc but don't know what to do from there. Didn't use time machine (sorry). don't have disks or anything. Live in a remote part of Mexico so assistance is not available. I use the school to teach English here so I am at a loss. Any help is appreciated.

thanks, Richard