Candi,
Welcome aboard and to the fun times ahead. They did you a favor by not including the hold down, you won't need it after a few practice cuts.
The bottom piece as mentioned earlier is suppose to protect your fingers if you reach under the table and play with the blade while the saw is running. Really?..I suppose some people need that kind of protection, but I'm sure you won't! Take it off and set it aside.
Just another hint: Forget the numbers on the tension handle,,,,cut everything at full tension and vary your speed according to the type of wood and intricacies of the pattern.
You're in for a lot of fun times and satisfaction!
Tommy T