Heh. What MGM said about practice!
A couple of other things. Unless it came with good strings (Aquila, Worth) you might want to try changing.
Make sure the action is low enough that you can fret notes cleanly. A very high action (common on inexpensive ukes before set-up) can mean that notes are difficult to fret - especially in bar chords - and unless you keep quite a hard pressure on the strings they can sound muffled or dead.
Make sure the action isn't too low! A very, very low action can cause rattles and buzzes, and can detract from tone and volume.
Action is a balance to be struck.
Try not to clamp the uke too tightly against your body. Obviously to hold it in the common manner with no strap you do need to keep it secure but if, like me, you're a bit on the chunky side, your gut can deaden vibrations in the back of the instrument. This effect is better known to mandolin players, who sometimes use a thing called a Tone Gard to keep the back of the instrument an inch or so off the body. The same thing can happen with ukes to some extent, so try not to muffle your instrument more than you need to.
But the main thing is what MGM said.