The theatre major gave me the foundation for the engineering side of what I do as well as the aesthetic side. There are many ways to research career fields of interest to you. The most common way is to complete an internship. There are many ways to be involved in the arts besides performing your art form. Getting to know the business side of the arts can be fulfilling.
Theatre is a risky career to go into, although very worthwhile.
Few of us actually make a living in it. You can hone your craft even if you are doing something such as creating training videos for the corporate world. Careers can take unexpected turns. If you are thinking about graduate school, there are graduate programs in the field of theatre as well as other professional degree programs. Then I had the opportunity to go into arts administration as my day job and this was such a good fit that I stayed.