head over to localbitcoins.com and see someone in your area for a cash - bitcoin exchange. I have done this with thousands of dollars, just make sure that they have a good rating and meet at a coffee shop or something. Another quick way is liberty x - GOOGLE: Liberty X. There may be Liberty X locations in your area. You can buy bitcoin with cash inside a store with Liberty X. The final option that is also fast would be a Bitcoin ATM in your area. You simply insert the bills and you get bitcoin to your wallet. Then use that to buy STEEM.