With the limited information that you have provided, I had to guess the problems faced by you. Some of it can be understood by reading below
Are you able to sync music but not playlist, is that right?
Do you have Apple Music Library turned On?
What error you get when you try to sync?
However...
In the iTunes app on your PC, click the Device button near the top left of the iTunes window. Select the type of content you want to sync (for example, Music or Podcasts) in the sidebar on the left. Select the Sync tickbox, then select the items you want to sync automatically each time you connect your device.
Sync iTunes content on PC with your devices - Apple Support