how can i see new movies
I think you misunderstood what Plex is. It is for streaming your own media which your Plex Media Server manages.
However there are Plex Channels that can be added as Plugins to provide access to some external material
See
What is Plex
You can read about channels here : https://support.plex.tv/hc/en-us/categories/200109616-Channels
then how can i shere a media
Please see the relevant support pages on the support portal support.plex.tv. Server Sharing is covered
