Here's a trick to easily check if the schema already exists, and then create it, in it's own batch, to avoid the error message of trying to create a schema when it's not the only command in a batch.
IF NOT EXISTS (SELECT schema_name
FROM information_schema.schemata
WHERE schema_name = 'newSchemaName' )
BEGIN
EXEC sp_executesql N'CREATE SCHEMA NewSchemaName;';
END