Default [Q] sprint lg g2 ls 980 twrp 2.6.3.2 no backup

so i installed twrp 2.6.3.2 i went to install cm11 it failed. I went to install my back my back was gone. adb sideload it say it can not read the file when i try to sideload a zip. i bought otg cables so i can mount but when i go to mount my usb drive doesnt show up what do i do?