Question

What makes the charges of electrons and protons negative and positive?

Answer 1

idk

Answer 2

we arbitrarily assigned the "negative" and "positive" labels as 2 different counterparts (probably because our numerical system is in terms of -ve and +ve numbers which cancel when added, i.e. -1 +1=0). They attract one another because systems seek the lowest possible energy configuration (potential in this case) which they achieve when they meet and become "uncharged". As far as i know, we don't know why these objects have said properties. There may be an explanation, in terms of elementary particles (e.g. quarks, leptons), i'm not aware of.