Jolt, you can definitely develop skill and fitness on the bike you have. It can be a great training bike, I'm sure. Just don't fall into the trap of comparing yourself to others. There are always going to be people much faster, and if they are on a road bike, that's a definite big advantage. Just keep working hard and you'll improve! Then, one day, you'll go for a spin on a road bike, and you'll just fly!