A non-exit row window seat is just like any other normal seat, except with a view. You have no additional requirements to sit in that seat.
The individuals who sit in the exit row have additional responsibilities. They're required to receive a briefing beforehand from the attendant, who will explain what they will be required to do in an emergency (possibly opening the door and lifting it out the plane). As a result, you need to be able to lift some weight, and have no physical problems that would prevent you from performing these duties.
While exact requirements vary by country and airline, frequently exit row passengers must:
Be of a certain minimum age, ranging from 12 to 18 depending on the airline's policies and/or local law.
Not be traveling with anyone requiring special assistance in an emergency (such as an infant or person with a disability), or an
animal (including service animals)
Have no physical or mental impairment that would hinder quickly reaching and operating the emergency exit.
Speak and read the national language of the airline's home country (e.g. English on Qantas, Arabic on Emirates or German on Lufthansa,
Not use a seatbelt extension.
Be able to lift 27 kg/60 lb (for window exits only) (Qantas requirement)
Passengers are typically required to operate "self help" or overwing exits in an emergency.
However, for every seat, window or otherwise, your sole responsibility in emergency or otherwise is to follow the instructions of the flight attendants at all times. Yes, the emergency row passenger has some additional tasks they may have to perform, but again, they will still just be following the instructions of the attendants.