You could make a box but you'd need some 1/4" stock to make the top and bottom. Simple boxes were some of my first projects.
Use a pattern like this:
http://www.stevedgood.com/ribbonbox.pdf but feel free to skip all the ribbon stuff. You're blocks aren't the same size as the pattern so just look at this to get the general idea. If you just shrink the pattern on your computer, the walls will be too thin.
Done worry about initials or anything fancy unless you want to really challenge yourself right out of the gate. Use the pattern for the basic idea. Measure in about 1/4" from the sides to mark out the exterior walls of the box. Cut that out. If you need to chew up the inside of that to get your corners (I certainly did at first!), take your next square for the interior walls. Put your exterior wall piece on top of the new piece and use a sharp pencil to draw around the *inside* of that piece. That will be the outside of your next piece. Measure in another 1/4" from there for the inside. Cut the inside and then the outside. Make sure they fit together and sand as needed until they slide in and of of each other easily. I needed to sand a fair bit until I got better at cutting straight lines.
Cut two 1/4" thick pieces to the uncut dimensions of your original blocks of wood (3 1/4" x 4 3/4"). Center your inside walls on one of these and glue + clamp it up. Glue the other piece to the outer wall piece. When the glue dries, the two pices will fit together to make the box. Just sand the outsides smooth and you'll be ready to finish.
If this is confusing, check out the picture on the bottom half of page two of this pattern:
http://www.stevedgood.com/businesscardbox.pdf That will show you how the pieces go together. Oh, and you'll probably want to use a #5 blade for this.
If that is a bit daunting, download Steve's pattern printer from his home page. You can probably fit some short-ish names on a block that size.
I personally don't think oak is a very friendly wood for a beginner. Your blade will want to follow the grain instead of your pattern lines which is frustrating at best. You might be better served to go back to Lowes and buy some poplar until you get more practice. It is probably worth a few bucks to make your early experiences good ones. Hope this helps.