My Try:

If someone is gonna be loved that person is you.

Eyer? That means saddle!

And we don´t need "da" here which is actually a conjunction and it needs to be written separately.

"Eğer biri sevilecekse, o sensin."

I´m sure it was said by a "romantic" Turkish man and I should say, if someone needs to improve his Turkish, that´s him.