Q: Sierra Install Failed But Wiped Out Everything!

I have Safari and tried to upgrade to Sierra, but it said there's not enough memory, though it still wiped out(?) most of my system.  I have no dashboard, no "About This Mac," very little at all.  NO, I didn't back up because I didn't expect any problems.  I thought my old OS would still be there if a problem with the upgrade failed...which it did.  I tried to repair disks and volumes, but a couple of them failed due to issues.

I've already lost all of my files and such, but all I really want at this moment is to get all the programs back that came with my 2011 Macbook when I bought it.  Chat NEVER seems to connect to anyone, and the stupid auto-robot calling system asks for my serial number which I can't even access anymore (see above).

Help, anyone?  I've also got a regular PC, thank God, but this nonsense is quite irritating.  I want my dashboard back, my control panel, I have NONE of that right now.

Thanks in advance!