grep

I was upgraded to Yosemite  from snow leopard when I  had my computer restored at Apple, and I have been lost on top of this mountain ever since.I am 81 yrs old and have been lost ever since.  I have taken my computer to Apple genius? twice and have had no success and very little actual help I now have no email and no address book.  I am unable to get i/cloud although I keep getting messages to install it..grep whatever that means.   I don’t have the strength or when I take it back to the geniuses?? I would throw the fool thing at the so called techs!