The amount of movies that a 32 GB flash drive can hold depends on the size of the movie that is stored on the flash drive.
Most 1 hour movies are at least 1 GB in size so at that size you could put 32 1 GB movies on the flash drive that is 32 GB.
If the movies are 2 GB in size then you could store 16 of those movies on the 32 GB flash drive.
Higher quality movies will use more storage and be bigger in file size than lower quality movies.
But you should get roughly 16 movies to 30 to 32 movies on a 32 GB flash drive.