Laptop Problems

i just bought this laptop :] for college
id like to know i what anti virus program i should look for ??
also do i need to purchase MS office ? because it asks me for sum sort of code everytime i try to use it ..
is this a good notebook ?
what are some actions i should take to keep it in good condition for ex. i was told to only charge it when the battery is low i was told over charging could slowly kill battery life ..
are they pretty sturdy ??
the battery life kinda sucks .. is there a way i can fix ithat ??
what are some thiings i should know about this laptop?
what are some accessories i should look into ?
thanks anything will help this is my first notebook and im stoked !!