I want to paint my bedroom furniture white and make it looked aged but I bought stuff at wal-mart to make it look crackled and I made a mess. What can I do to achieve an aged look on my furniture?

It's called "antiquing". There are a variety of methods, here are some ideas:
http://www.google.com/search?num=100&hl=en&safe=off&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=antiquing+furniture&spell=1

One easy way is to paint a base coat,
For this method, a light color works best (white)
Once that is dry,
Pour a little brown paint into an empty, clean bucket.
Add water to the paint (until the paint is so watery, that it drips off a paintbrush)
Get a clean, dry cloth,
And dip a small area of the cloth into the paint and water mixture.
Working a small area of your furniture at a time,
Rub the dipped cloth onto your furniture,
(in a circular motion)
Then wipe it off (with a different dry cloth)
Before it dries.
Keep on doing this until your furniture is covered with the paint and water mixture.
Once it is dry, if you would like your furniture a little darker,
You can repeat the process.
Just apply the mixture directly over the dried application that you rubbed on earlier, and let dry again.
It is best to do this outside.
To keep your paint from chipping, or being rubbed off,
You should put a varnish coating on the entire piece.
This can be time consumig, but it's cheap,
And the outcome is well worth it.
Hope this helped, Good Luck

My advice is to have both aged and modern pieces in your rooms