Msg 156, Level 15, State 1, Line 21 Incorrect syntax near the keyword 'create' - sql

Question

USE master;
GO
CREATE DATABASE Sales
ON
(NAME= Sales_Data,
FILENAME = 'F:\\DB\\Customer DB\\Sales_Data.mdf',
SIZE = 10,
MAXSIZE = 50,
FILEGROWTH = 5)
LOG ON
(NAME = Sales_Log,
FILENAME = 'F:\\DB\\Customer DB\\Sales_Log.ldf',
SIZE = 5,
MAXSIZE= 25,
FILEGROWTH = 5);
GO
USE Sales;
GO
CREATE SCHEMA Sales_schema;
CREATE SCHEMA Production;
USE Sales;
GO
CREATE TABLE Sales.sales.customers
(
customer_id int,
first_name varchar (15) NOT NULL,
last_name varchar (15) NOT NULL,
email_address varchar (50) NOT NULL,
phone varchar (15),
state varchar (15),
city varchar (15) NOT NULL,
street varchar (30) NOT NULL,
zip_code varchar (5) NOT NULL,
CONSTRAINT customers_uq UNIQUE KEY (phone),
CONSTRAINT customers_pk PRIMARY KEY (customer_id)
);
CREATE TABLE Production.categories
(
category_id INT PRIMARY KEY,
category_name VARCHAR (20)
);
CREATE TABLE Production.brands
(
brand_id INT,
brand_name VARCHAR (20),
CONSTRAINT brands_pk PRIMARY KEY (brand_id)
);
I expected no errors at all, but I found multiple errors. Please check these unexpected errors
Msg 156, Level 15, State 1, Line 21
Incorrect syntax near the keyword 'create'.
Msg 1801, Level 16, State 3, Line 26
Database 'SALES' already exists. Choose a different database name.
Msg 156, Level 15, State 1, Line 46
Incorrect syntax near the keyword 'CREATE'.
Msg 156, Level 15, State 1, Line 63
Incorrect syntax near the keyword 'key'.