Is it permissible to deliver the Friday sermon, memorized from shaykhs, despite having little knowledge, but with good delivery?

If a qualified and knowledgeable preacher is available, you should not put yourself forward before being prepared, due to the saying: "Beware of these altars," meaning the mihrabs (prayer niches from which sermons are delivered). However, if no one else is available and you are needed, then there is no harm in you delivering the sermon, as long as you convey from trustworthy scholars, while being careful not to speak about Allah without knowledge.