If you apply to MSU Special Education program and are accepted, all 12 credits from your internship program many count if you have passed these courses with a 3.0 or better. You then have 5 years from your earliest course to complete your masters requirements.
Some, but not all of your 800 level internship courses may count if you apply to other MSU Masters Programs.
If you choose to apply to another university, all of your courses will be reviewed and a decision made. Other universities are under no obligation to accept credits from another university. It is a good idea to keep all syllabi and course descriptions of your courses. Sometimes this will help another university to make a determination in your favor.