Can Friday sermon be in English and what should be in it?

Yes, it is permissible to conduct the Friday sermon (Jummuah Khuttbah) in English in case of the absence of Arabic speaking Muslims. It is generally permissible to translate the Friday sermon, after conducting it in Arabic, into any other language.
The Friday sermon should contain praising Allah the Almighty, invoking peace and blessings on the Prophet and commending Muslims to fear Allah. It is recommended for the Imam to recite some verses from the Qur'an and supplicate to Allah in the second part of it.