What Kind of Career opportunities are there in Singing?

Depends on if you are any good or not. A lot of people can make money and a living out of it without being famous. Cruise ships, hotels, theme parks and various other places have people that sing all the time and it's not as hard to get a job at those places as it would be to land a record deal. However, you must be located near a place that offers these jobs.

There are back up singers that recording studios use, as mentioned there are people who have contracts with large nursing home groups that travel from home to home singing daily for them. There are hotels, all of the small and large theme parks and all of the 1000's of music groups in places like Dollywood area, Branson area and the such.

There are teaching positions, there are voice coaches ( almost all major and medium professoins have voice coaches) for every number one hit performer, there are 10's of thousand people who barely make their expense money in performing.