The easiest and fastest way to obtain bitcoins instantly is to acquire it from market.
Precisely.
It does depend to where you are comfortable with. Interest is there already and you only need a way in order to acquire an amount. There are already good suggestions in this thread and also to other topics concerning the same, in this forum in which you will be able to get knowledge from. Just to add, if it is not yet mentioned, airdrop could yield to free money but I'm not sure if this is still profitable at this moment, since the time or year wherein I experienced such method to be profitable is during 2017/2018 . But you are free to read about it and try it yourself. But if it is the easiest way you are looking for, that is indeed correct, try investing into it.