Online Survey Companies - best way to make cash while also studying at univ?

Hi guys,

I am 18 years old, live in Portugal (Lisbon), studying Law 1st year and would enjoy to get some cash, although I cant hinder or in any way harm my university degree, study and dedication, so it could not take a lot of time and mental and physical energy as it would take an opportunity cost which I cant afford as I need to focus on my degree and lift my grades up...

My obstinacy to generate monetary resources lies on... my family, well, is not in the best economic condition right now and secondly because I would like to gain more economic and therefore social independence and not force my parents to pay for all my whims and ****. Like I want to act comfortably to the extent that I can buy some clothes or snickers I want to or these summer holidays go on an interrail w some friends or go spend some weeks on a cool idyllic place w my buddies. Or even to invest by my own, consistently, for example on the stock market, which as you know takes a lot of input capital.

I have registered in some online survey companies which seem to pay considerably well considering the scant amount of time and effort I will be taking. Do you know some online survey companies that reward the best and are prestigious in the market and are not like fake (I kinda fear that). Or do you know any other way or employment which doesnt take much time and energy from what really matters (univ) and idk requires writing and creative skills? I am good for that and enjoy it, which may make it easier to succeed in the business.

Thanks