So here's what I know
The Anglos, the Saxons, and the Jutes were some of the first to settle the UK. Denmark ruled the northeast of modern England for several hundred years before the Normans. Danish rule also brought other groups like the modern Norwegians. The Normans themselves were Scandinavians that migrated to France. Before the Anglo-Saxons, you had the Romans ruling over the Celts. The Celts displaced the Picts and other minor groups.
From the UK first being settled up until Winchester becoming the capital in 871CE, what other details am I missing?
Can you narrow down a specific time frame that you're looking at? The arrival of people into the UK extends back into prehistory and continues up to today.