1. chra -> hra - should be easy
2. bą -> bon - nasal, like bon in Portugese (for example bon dia)
3. szcz -> shch - both sh and ch must be heard separately
nasal, like bon in Portugese
in Portugese it's actually bom dia, not bon dia, but it's almost the same; bon dia is in Catalan
But you have "bon" also for example in French.