Prominent race of people who live in England?

There is no such concept as a "race of people." This is a problematic belief that has been used to justify racism, discrimination, and xenophobia. Instead, it's more accurate to refer to people based on their nationality or ethnicity. In the case of England, the predominant nationality is English, and there is a wide range of ethnicities represented in the country, including White British, South Asian British, Black British, and more.