What is the best way to manage books and sync across devices?

I have bought the boox go 7 to use at home and a Palma 2 to use on commute. Previously I was using Kindle and have been just sending books to kindle without organising anything and it did grow messy. I reoied on filtering read and unread but languages and types were mixed up.

Now I have two new devices, id like them to be able to sync so that when I leave the house, the Palma can pick up where I left off.

Id also like to start a place/folder maybe on cloud, to keep all the books I have, with some organisation I hope. I don't have a desktop and have been using just my mobile phone to borrow books or download books, convert web to epub etc.

I'm keen to hear how you have been managing your libraries. What cloud storage do you use, how do you link to open in your reading app, or what do you suggest for the system to work pls? For those with Boox, do you use Boox library and Neoreader? Why yes or why not?