OK, a serious question. Who is this Taylor Swift person and why does Trump hate her?

shes a popular musician and not a fan of trump

Taylor Swift is an associate professor in musicology and music history at Johns Hopkins University studying early Americana folk and pop music.

She’s a famous woman who’s richer than him.

By the way, who is that Trump guy, and why does he brag that Viktor Orban values him?

She's a woman who is endorsing another woman.

She has had a great deal of success by means of the products of her own creativity, without inheriting anything or promoting hatred of anyone.