very slow and freezes asus x556uq 7th gen intel core i5

Dear All

I have bought this notebook for office work and it is very slow , no heavy software just office and symantec antivirus.

asus x556uq 7th gen intel core i5

i tried to check startup

updates

disk space partition

nothing works

please let me know what kinda ram I should by to get this device faster

what to do please help

im broke and helpless