This is the 2718th most frequent Arabic word.
بعضا
"Some" or "a part of."
In this context, 'بعضاً' indicates a part or portion of the book; it specifies an unspecified amount.
قرأتُ بعضاً من الكتاب قبل النوم.
I read some of the book before sleeping.
Here, 'بعضاً' is used to quantify the advice provided, denoting that there were several useful pieces of advice given.
أعطاني أصدقائي بعضاً من النصائح المفيدة.
My friends gave me some useful advice.
In this case, 'بعضاً' expresses an unspecified amount of time that is hoped to become available.