Answer:
-To start off, the first thing to look at is which letters can have accents. These are only the vocals (a, e, i, o, u), no other letter can have accents in Spanish.
-Words in Spanish are divided into syllables. Syllables are, usually, a consonant followed by a vocal (or the other way around). Here is an example with the word "caballo": ca-ba-llo (this word has three syllables).
These are the accent rules in Spanish and they're actually pretty easy (even though natives often struggle with them). The screenshot I sent you contains the rules. Note that the rules in the image are not all of the rules but they account for most Spanish words. The rest of the rules are a bit more complex but I can give you some basics on them (if you want more detail ask me and I'll send you a more detailed response):
For words ending in "-ía" they are always accentuated if the emphasis is on the "i".
For words ending in "ú(h)o/a" they are always accentuated if the emphasis is on the "u".
Good luck with your test.