Typically when you're working with a Realtor to find properties, the SELLER pays the commission on the transaction, not the Purchaser. Unless you've hired an Exclusive Buyer's Agent to represent your best interests as a Buyer, in which case you might be responsible for the Agent's commission (depending on what commission the Agent can earn through a MLS sale from the Seller).
I've been helping First Time Buyers for 23 years as a mortgage professional and I will tell you what I have always told my clients here in New York: If you are a First Time Buyer, steer clear of foreclosures and short sales.
Foreclosures are someone else's headache. The home probably has not been well-maintained and you're a First Time Buyer adjusting to paying a mortgage. Do you really want to walk in the door to someone else's deferred maintenance that YOU will have to pay for? Also, if you're thinking there are deals to be had in terms of lower prices, mostly those "deals" go to professional investors who can pay cash, negotiate hard with a Lender, and close fast.
For Short Sales, my attitude of late is that First Time Buyers should steer clear. Short Sales tend to be a better deal for the homeowner than for the Buyer. You'll wait MONTHS for the homeowner's Lender to approve the short sale; maybe as long as Six or Seven Months. Meanwhile, you're stuck in a contract to buy that home. I closed a short sale recently with a Buyer who, after seven months said this at the closing table, "I don't even want this house anymore."
And he didn't even get the "deal" on price he thought he was getting! The house appraised for only slightly more than he paid for it at the short sale price. He walked into this deal thinking he was buying a home for $100,000 less than it's value. In the end that wasn't the case.
There are plenty of motivated Sellers with their homes listed on your local MLS. Go find a good Local Mortgage Banker, get prequalified, then find a great, experienced Realtor, and buy the home you want at the price you're willing to pay. It's a Buyer's Market, after all!