How to correctly start using a brand new Extreme PRO 128GB USB 3.0 Flash Drive

I am about to start to use Extreme PRO 128GB USB 3.0 Flash Drive
I intend to use it to backup files both in iMac High Sierra 10.13 and also on Windows 10 Home 64 bit computers.
Could You please give Me detailed information of how to
a. Initiallize pen drive (if necessary)
b. create 2 partitions: one to use with iMac, and another one to use with Windows 10. (please also show me how to assign sizes to each individual partition. Is there a maximum number of partitions allowed to be created? Is there a minimum size for any partition?)
c Which OS should i be creating partitions with (or from)?
d. If they are encryptable please show Me how to do that.

I would much appreciate your help with this matter.

Thank You kindly.
Carlos V.

Note: Does Sandisk offer online chat support?

Hi @estos.son.boludos,

Have you opened a Support Case? If not opened, for more information, please contact the SD Technical Support team for the best assistance and troubleshooting:
https://kb.sandisk.com/app/ask