How to insert values to a table from 2 foreign keys
You have two issues: 


A typo in your GradeInfo table definition that should be a syntax error, but unfortunately sqlite is all too often too lenient about what it accepts:

FOREIGN KEY (Student_ID) REFERENCES StudentInfo (Student_ID)
FOREIGN KEY (CourseNo) REFERENCES CourseInfo (CourseNo),


Notice the lack of comma. (EDIT: This actually works even though it shouldn't! Bug in Sqlite?)
The primary key on CourseInfo is (CourseNo, Year), but your foreign key only references CourseNo. You have multiple rows in CourseInfo with the same value for CourseNo. Which one is supposed to be used as the parent to the foreign key? Add tracking the year too to the table and it works:

  CREATE TABLE GradeInfo (                    /*Created 3rd*/
    Student_ID NUMERIC AUTO_INCREMENT,
    CourseNo Text,
    Year Numeric,
    Pts NUMERIC,
    Grade TEXT,
    FOREIGN KEY (Student_ID) REFERENCES StudentInfo (Student_ID),
    FOREIGN KEY (CourseNo, Year) REFERENCES CourseInfo (CourseNo, Year),
    PRIMARY KEY (Student_ID, CourseNo, Year)
    );
INSERT INTO GradeInfo(Student_ID, CourseNo, Year, Pts, Grade)
VALUES(7007, 'INFO151', 2018, 15, 'A+');



Also, there's the double quote vs single quote issue that sticky bit mentioned already, and AUTO_INCREMENT is not a sqlite keyword - you should read this documentation about auto increment and how to use it (If you really need it; you usually don't; an INTEGER PRIMARY KEY is enough).