Trip to Belgium (Bruges-Ghent-Brussels) - public transport, tips, anything I should know

Hi All! I’m currently planning my itinerary for Belgium and need your help with tips on public transport. My plan: Brugge, Ghent, and Brussels. I will arrive at Charleroi Airport, and my first stop will be Bruges. Can you recommend the best form of public transportation?

How many days would you suggest spending in each city? My plan:

Brugge - 2–3days

Ghent - 2–3days

Brussels - 1–2days (some people said it's not a big deal)

Thanks!