Have an Answer?
The Marine Corps, like the Navy and other branches, has jobs, rates, MOS for almost any and every field you can imagine. the real question is: What are you interested in doing? Once you find that out, you can look for the MOS that matches you. Next, if you have time, get ASVAB study guide and practice tests (check local library) to hone your test taking skills until you can get the ASVAB score necessary for that MOS, rate, job.
You can go online to the Marine Corps website to see all the "roles in the corps" page. But in my limited experience, if you do very well in the asvab in a particular area, they will come to you with the best suited MOS. Then you have some bargaining power. Use it wisely as it will most likely shape your life for the future. Think about what skills you want to have when you become a civilian again, as well as being prepared for work when you are no longer a Marine.