Planning a trip with my wife and parents in 2nd week of June, Please suggest itinerary, trusted hotels, spots and attractions to visit.

We are going via Chandigarh and are also confused if it is better to take a overnight bus or book a taxi for 4 people and reach the same day to Manali instead of spending time in Chandigarh in the day. We want to cover Manali and Kasol in 5 days. Also, Should we book hotels in advance using online platforms or is it better to visit hotels yourself and book offline to avoid scams? Need suggestions, Thanks in advance!