Installed El Capitan now problems

HI,

i have previously posted that after I installed OS X El Capitan on my MacBook Pro mid 2012 that I have unresolved problems with resarting and shuting down from the apple in the top left corner. I always must use my power button to shut down.

Now I am thinking that maybe I also have startup irregularity. When I press power button to start up I always see a white screen with apple logo with bar underneath showing it is loading something by filling in the bar with grey as it goes and then when the bar is filled in it does indeed take me to sign in screen.

ALso, when I went to my second login to see what happens there, the computer took over and set up guest user which if I now try to delete , I can not. The minus button on the account is greyed out. I tried from my main login to do this.

there are are most likely other issues but I am too busy trying to fix the shut down problem to do anything else on the MacBook Pro.

Regards

pab