These are the basic polyatomic ions (known as polys, for short) that you must have memorized before the start of chapter 5.  You need to memorize their formulas (including subscripts and superscripts) and names exactly.  I recommend making flash cards.

I have broken them down into "related" groups to make it easier to memorize.  Start with group 1 and proceed from there, at least 1 group per week.

Group 1-note the common suffixes! Group 2-note the common suffixes! Group 3-note the one different suffix! Group 4- exceptions to the usual suffix
NO3-   nitrate

SO4-2   sulfate

PO4-3   phosphate

CO3-2   carbonate

ClO3-   chlorate
BrO3-   bromate
IO3-   iodate

 OCN-   cyanate

CH3COO- (or C2H3O2-)   acetate

MnO4-   permanganate

C2O4-2   oxalate

 CrO4-2   chromate

Cr2O7-2   dichromate

NH4+    ammonium

 OH-   hydroxide

CN-    cyanide

O2-2   peroxide

Once you know all of these, you will be taught a few simple rules for all the other polys that you need to know for this course.