Troubles

1997 gmc jimmy 98,000. Iv been having trouble with my car. When I start it, it usually has a hard time starting but then it will. Once I put it into gear it will usually shut off, but then sometimes it may take 5 or 6 tries to actrually get my car going. Also when im driving my car will beep and all the gauges will drop and the air back sign will flash. It will also say check gauges when my car shuts off.