Hello Gary817, and welcome to the community!
You have multiple ways to download data from your Raspberry Shake, all listed here: How to download your data
Currently, the FDSN Web Service is unavailable, due to a severe server issue that involved our systems, so you will have to jump to the From the Raspberry Shake section. We apologize for this inconvenience You can follow our constant updates here: Live Data Issues
Once you download the raw miniSEED data, you can then elaborate them to obtain displacement/velocity/acceleration in different ways, such as via MATLAB, ObsPy, SWARM, and more. We have basic Obspy counts-to-metric code available here: Developer’s corner and you can find much more on the ObsPy main documentation page: https://docs.obspy.org/
Regarding your second question, DataView will display all data from any station for as long as the station is connected to the network. However, due to the server issue described above, only the last 24-36 hours are visible (legacy data is not deleted; it is simply not accessible for now).