First, You can't be English. That isn't a thing. But yes, it is fine to date someone who is "Spanish" And knows English. I am assuming by Spanish you mean someone from a Spanish speaking country or of Spanish speaking heritage.
Yes! It's perfectly normal to like a variety of people... No matter their heritage or gender you are just showing love! It doesn't matter! Screw the people who say you shouldn't date them. It's your decision.