Can anybody help me to solve these problems?

I just recently upgraded my Lg device named lg v10 from 5.1.1 lollipop to 6.0 marshmellow and firstly i was stuck in boot loop issue and after I somehow manage to fix it and i see some more problems in my android first that i cant set up a lock second i cant uninstall any app and third my phones setting stops working as i try to access security any body plz help me....

Welcome to Android Central! Was this an official system update pushed over-the-air to the phone, or did you download the update manually from some website?