Is there a direct Ferry from Naples to Positano?

Hi Tamara -
No, there are no direct ferries from there. You can explore available ferry routes here using the "departure" and "arrival" dropdowns.

https://www.positano.com/en/ferry-schedule

If you mean non-stop. No.

Coming from Naples what would be better, fast train to Salerno then ferry to Positano, or to make our way to Sorrento & Ferry from there to Positano.
Thanks in advance 🙏

We did neither -- ferried to Sorrento and then took the bus to Positano. That worked for us.

You could also take the train to Sorrento and then the bus to Positano.

My choice would always be to take the train to Salerno and ferry up the coast to Positano. My reasons being that if you take the local train to Sorrento from Naples with luggage, you could have a less than pleasant experience. The local train, the Circumvesuviana, has an unsavory reputation. We took it once without luggage and it was a very unpleasant experience! I don't know what time of year you are making this trip, but the SITA bus from Sorrento to Positano could be packed. With luggage, even more challenging. By taking the train to Salerno you avoid the Circumvesuviana, and you arrive at the train station which is not too far from the ferry dock. There is more room on the ferry, and the view of Positano from the water is breathtaking!!