This is some of the very basic stuff, so you definitely need to know that. Neuter is one of the genders (the third one in singular, apart from masculine and feminine), Nominative and Accusative are some of the cases. You can read more about genders here and about cases... I guess you should check the links in the "CASES" part of the post here.
this: ten/ta/to (masculine/feminine/neuter), ci/te (masculine personal/not masculine-personal)
for "that" you just add "tam" at the beginning of the pronoun
And then you need to remember that Polish has levels of closeness: ten/ten/tamten, while English has this/that/that, so they overlap.