Choosing my name for my first publication I'm publishing my first ever paper in my career. Given my name is Aaron John Sabu, how should it be broken into the first name and last name? 

Also, what should I write when asked for the [Initial][Surname] format?



NB: Aaron is my name, Sabu is the name of my father and John his father.
Also, I do not have a proper surname since it is not part of our custom.
@Buffy's and @user2768's answers raise good points to consider when choosing. 

I'd like to recommend in addition: Get yourself an ORCID and use it. An ORCID is a unique identifier that you can keep, however you may later on decide to change your name again.

ORCID allows several names, they say the only one really required is the first names (which can also be multiple first names) in order to also work for cultures like yours. So you could leave surname blank and actually keep your name as it is.
You can also specify how you'd like to be cited (I'm not sure how many look this up, though. But literature data bases should hopefully get that right), and you can even give also-known-as names. 

As a side note: while it's good to think a bit which name you like to use, it's not that you cannot change it if it turns out not to work as well as you thought. If you use an identifier like ORCID, this won't even lead to confusion whether it is still you.
(And people in western culture do change their surnames as well, e.g. when getting married or divorced.)



It's not that western cultures don't know patronyms (usually with some change, e.g.  prefix or suffix meaning son/daughter, diminutive or genitive). In many western countries they meanwhile became family names but AFAIK in Iceland it is usual (and Denmark  possible) to give children a proper patronymic or matronymic name. They put the patronym/matronym as surname - so if you don't know the name of the parent, you don't notice the difference between a proper patonymic/matronymic or one that meanwhile became family name.