Can you please explain the difference between Beit Yosef meat and Ashkenaz meat? Also, may an Ashkenazi person eat Beit Yosef meat?

In two words – the Beit Yosef is stricter on how to define kosher meat and in what way to assure the meat is kosher and not Treif. Therefore an Ashkenazi that follows the lenient opinion of Rema can obviously eat "Beit Yosef meat" but not vice versa. It's recommended for Ashkenazim also to follow the strict opinion when possible.