I am looking for a good groundcover to stop weeds and I saw that creeping phlox was recommended. I also found some sites that explain how to grow it from seed, but I can't find any place that sells creeping phlox seeds. I search online for at least 20 minutes without any luck. I would like to buy it in seed form since i have a large area to cover. Do you have any suggestions on where i could get some?

There are at least a couple of Phlox commonly called "creeping phlox."
Are you trying to find Phlox subulata?

If so, I can't recall having seen seed being offered for sale. Around here, the big box stores get tons of it delivered in the early spring when it's blooming and then usually clearance them off pretty cheap when they stop blooming a few weeks later. You may want to keep an eye out at your local Lowe's, if you have one. You can often split pots of overgrown groundcovers, too, which can save even more money.

I have creeping phlox, Coral Eyes and while it is a great groundcover you will still have to pull some weeds. Some weed seeds always seem to find there way to the ground and pop up right in the middle of the phlox. It doesn't happen all the time but I didn't want you to think you could just plant it and never see any weeds again in that space.