you need to use a joined query to merge the 3 tables together, for example the following query:
SELECT student.student_name, courses.course_title
FROM students_courses
INNER JOIN student ON student.student_id = students_courses.student_id
INNER JOIN courses on courses.course_id = students_courses.course_id
returns the following result
+--------------|--------------|
| student_name | course_title |
+--------------|--------------|
| mike jordan | algebra |
+--------------|--------------|
| mike jordan | chemistry |
+--------------|--------------|
| mike jordan | chemistry |
+--------------|--------------|
| oscar ortega | history |
+--------------|--------------|
| oscar ortega | algebra |
+--------------|--------------|
| oscar ortega | chemistry |
+--------------|--------------|