I have never had a smartphone before and there is very little info that came with this phone. I want to buy an SD card for it and found one on Ebay but it has this warning: YOUR DEVICE MUST SUPPORT AT LEAST 128GB OF EXTERNAL MEMORY. How can I find that out? Is there a specific kind I should get and if so how do I find out what that would be? I would appreciate any help I can get. Thank you in advance.