Some TV broadcasts or YouTube uploads split this 90-minute TV movie into two parts for commercial breaks. Therefore, "Parte 1" is simply the first half of this same film.
However, there is an important clarification: specifically titled "Santa Rita de Casia: Primera Parte" . The most famous and widely available film about her life is simply called "Rita de Casia" (sometimes listed as "Santa Rita de Casia" ). pelicula de santa rita de casia primera parte en espanol
Here is the feature film you are likely looking for: Some TV broadcasts or YouTube uploads split this