It's very unlikely that you will be able to buy a property at a sheriff's sale for 6K, but it is possible. You need to do a lot of research on those to make sure you will be getting them free and clear, most will be encumbered by a first lien or they will be priced too high to purchase for 6k cash.
MLS is Multiple listing Service, there is a very good list of terms on the site, I don't have the link right now but I'm sure one of the regulars will have it handy.
Go to a couple of Sheriff's and foreclosure and tax sales just to get an idea how they work, DO NOT take cash, lol, until you have a good idea whether that is what you want to do. See what gets sold, look at the properties afterward, research them on the county tax/public records sites. Those sales are cash only, you usually have one hour to pay. You can buy a list of properties usually and you may find a regular who would be willing to let you look over his shoulder.