if u miss the khutba, you miss a great reward.. but if u missed both khutba and salat of jumaa you then missed the whole jumaa, and that's a sin.. and you have then to pray 4 rakaats as Dhuhr

Khutba hajj tul

You cannot offer juma prayer at home alone, it must be offered in congregation (jamaat) whether you arrange it at your home or in the mosque with other people. You should listen to the khutba of the Imam. ...

Khutbat Al-wadaa or "The Last Sermon" is the last sermon of the Prophet Muhammad, peace be upon Him.

It is the last public speaking & advice of Him to Muslims since He PBUH had died few months after delivering that impressive sermon. It was delivered in the valley of Mount Arafat (in Macca) on the Ninth day of the Lunar month of pilgrim (Dhul Hijja) on the occasion of the pilgrimage of Muhammad PBUH & His companions & fellows.

It contains much great effective words as all the words of Muhammad, may Allah grant Him with peace & blessings.

Friday, for Muslims, is a holiday. All Islamic countries (at least the Middle Eastern ones) take Friday off. Every Friday there is a Jumaa. The Imam gives a Khutba and anyone who attends it from the beginning is attending salat duhr. After the Khutba, they pray 2 rakaas for the duhr.Also, the Prophet pbuh prayed at the mosque on Fridays. Truthfully, a man should be praying all his prayers at the Masjid. That is including the Fajr.