Hi,
I'm not sure which slot you are referring to. If you have the screen towards you, on the left side you have the USB cable port and also the charging dock connector. At the right side, you have the nano- and SD-card slot. In the right slot there is also an OFF button which you can use to force a shutdown of the device.
My apologize, I thought you had a phone in the Z3-series (ignore above). In the slot for Z5 compact (checked your other thread) you have the slot for the Nano-SIM and the SD-card. Next to the SD-card slot, you have the label tray where can find the IMEI-number:
http://support.sonymobile.com/global-en/xperiaz5compact/userguide/IMEI-number/
You also have the OFF button which you can hold down with a paper clip for example to force a shutdown of the device.
I would choose a MicroSD-card with class 10 or UHS-1 but a MicroSD-card with class 6 works great for HD and Full HD recording.
