Mysql problem w/ create table

[Felissa]

I have an assignment to make from my teacher but I cannot reach him I am a beginner in sql can somebody help me maybe? The problem seems to be in the auto_increment maybe? Or with the not null default now(), which I do not understand what it means.

Thank you!
Greetings from Holland

CREATE TABLE Order (
    Id                   int                    auto_increment,
    OrderDate            datetime               not null default now(),
    OrderNumber          nvarchar(10)           null,
    CustomerId           int                    not null,
    TotalAmount          decimal(12,2)          null default 0,
    constraint PK_ORDER primary key (Id)
);