Hi, Izzat Hannah,
Do these two sentences have the same meaning?
Helen said she loves visiting New York.
The usage of 'loves' clearly indicates that she still loves visiting it.
Do these two sentences have the same meaning?
Helen said she loved visiting New York.
Here, we don't know if she still loves visiting it or not. What we know is that she loved visiting it at that time. Maybe that happened a long time ago, and she has a different opinion now, or maybe she still loves it.
A: Does Helen love visiting New York?
B: Yes, she said she loves visiting it. / Yes, she said she loved visiting it.
Of course the best answer is 'She says she loves visiting it.'.