Most hand-comfort problems are a result of saddle adjustment... if your saddle is tilted nose down, you will have to brace yourself from sliding forward with your hands. Saddles should be perfectly level when viewed from the side (or very slightly nose up - nose down causes problems). If the saddle is uncomfortable then other adjustments are necessary... changing the saddle perhaps...

But, as said above, get th bike fitted. But adjust the saddle angle before you do anything... you might be surprised at the result.