Can the forms be finished later and if so how can it be set up?

If so, how do I set that up so they can come back to it later without loosing their data?

Yes, that is possible and we have two ways to achieve that.

You can see more about it on this thread here: Can we make a jotform that could be continued at later time?

Of course if you have any questions along the way, we are here so do let us know.