[Work on a document on more like one Computer]

Hello, i have a question concernig a big document what i already started with affinity publisher on a laptop. Now i downloaded the publisher on my PC. Could anybody help me for solving a transfer of the data. What is the best possibility to get the raw data on my PC in best resolution? Because just saving and open shows a very bad resolution of pictures and diagrams. If i export it in PSD file i get hundred single pages. Means also a lot of work to combine again. In PDF export i get i nice format and i also can work with it. But is PDF realy creating good resolution and quality in the end?

The best wood be an online cloud, does affinity offer any cloud where i can load up a project in best possible quality, not only a downsized document what is in need of my pictures and diagrams that are saved local on my laptop?

Thanx for your help, would be realy nice if anybody has an advice.

Greetings Bernhard