Error Code 1064, Cant figure this out
You will need to respect MySQL syntax, here's something that passes the muster of DB Fiddle  (MySQL 5.7).  See https://www.db-fiddle.com/f/kMfBNBx9WRe65cwWyRmUMn/0

CREATE TABLE nation (
natcode CHAR(3),
natname VARCHAR(45) NULL,
exchange_rate DECIMAL(9,5) NULL,
PRIMARY KEY (natcode));

CREATE TABLE stock (
stckcode CHAR(3),
stckname VARCHAR(45) NULL,
stckprice DECIMAL(9,5) NULL,
stckqty DECIMAL(9,5) NULL,
stckdiv DECIMAL(9,5) NULL,
stckPE DECIMAL(9,5) NULL,
natcode CHAR(3) NOT NULL,
PRIMARY KEY(natcode),
CONSTRAINT natcode
    FOREIGN KEY(natcode)
    REFERENCES nation(natcode)
    ON DELETE RESTRICT
    ON UPDATE NO ACTION);


INSERT INTO nation (natcode,natname,exchange_rate) VALUES
  ('AUS','Australia','0.46'),
  ('IND','India','0.0228'),
  ('UK','United Kingdom','1'),
  ('USA','United States','0.67');