Is a Honda CRF50 a good bike to learn on?

Is a Honda CRF50 good for learning on. But what's is the horsepower on it and how fast would go

Depends on your age and height to be honest.

The CRF50 is an off-road bike, not road legal. You can't use it on the road. You can only use it on private land with the land owners permission.

If you're in your teens, then I'd go for something like a Yamaha TTR125.

A Honda CBR125 would be a good bike to learn on.