No, you don't have to post a picture...unless you want to and especially if what you want to show me has different notes than what's shown in the first 8 measures. Judging by the first 8 measures, it looks like you might have the same pattern of notes all the way through the piece. Again, that's not a sure thing that you repeat the same pattern throughout the entire piece, so maybe posting a picture would be good.
Not to be mean or knock on your school's music program or anything but...isn't the point of being in a band or orchestra to learn how to read music (at least in the beginning classes anyway)?

I'm just a little curious about that. I know I wouldn't feel comfortable if I had to perform a piece of which I was unsure of the notes in a concert the next night.

I'm not sure how much help I can provide you. First, I don't know how much you know, so I'm at a loss on where to begin. Also, I'm a violinist so even though the piece you're showing me is in treble clef (do you at least know what I'm talking about when I say that?), which is what violinists use, I'm not confident enough in my knowledge about percussion instruments to say with conviction that a B-flat on the mallet sounds the same as a B-flat on the violin. My guess is that it should be okay though. Enough of my babbling and on to the music.
Do you know how to read a music staff? On a treble (or G) clef (which is the clef your music is played in), the "space" notes spell FACE (the first space is an F, the second is an A, and so on). The way I used to remember the "line" notes on a treble clef before I started to memorize where each note was is to remember the mnemonic "Every Good Boy Does Fine (the first line is an E, the second line is a G, and so on)."
HERE is a page about clefs that you can look at.
One other big thing to note is that you've got 3 flats in the piece (you can see 3 of them at the beginning of the piece, right in between the clef and the time signature, which is 4/4). This is called your key signature (you can read about it
HERE but hopefully you know what I'm talking about). Being an orchestra student for a big chunk of my life, I didn't usually see key signatures with many flat notes in it as much as band students did; at the very least, we knew that the first 4 flat notes spell out BEAD. That is, if one flat is shown in the key signature, instead of playing a regular B, we would have to play a B-flat instead. Every B in the piece would be played as a B-flat. If two flats are shown, you'd have to play a B-flat and E-flat, and so on. In your case, you have to play a B-flat (instead of a regular B ), an E-flat (instead of a regular E) and an A-flat (instead of a regular A). The reason why key signatures are used is so that all the flats, sharps, and natural symbols wouldn't all have to be typed out onto the sheet music, which saves ink and makes it look less messy. The musician would then be responsible for knowing which notes to alter throughout the piece at one glance of the key signature.
Based on this, in the first 8 measures of your piece, each measure reads B-flat, C, E-flat, F (natural), E-flat, C, B-flat, C, E-flat, F (natural), E-flat, C. It repeats like this, at least for the first 8 measures you've shown me.
I'm hoping that this information is helpful to you. I won't be able to tell you how to find these notes on your instrument because again, I'm a violinist and my knowledge of percussion instruments is only as much as what Google tells me. I apologize if I've given you tedious information that you already knew. Again, I don't know how much you know so I thought I could start at the very basics. Let me know if anything is overly confusing and I'll do my best to help you out.
I'd feel much better about the advice I'm giving if someone with more expertise with percussion instruments could back up my words (anyone?).