Recently I've asked this question on MSE which has in fact two questions on it:
Describe all $R$-modules of low order (up to isomorphism)
Later, I realized that in two different posts there were answers that solve my questions, namely $\Bbb F_2[X]$ modules with 8 elements and Isomorphism classes of $\mathbb{Z}[i]$ modules.
I flagged my post as a duplicate of the first one and they were linked each other but I didn't know how to link to the other post. Can I do this or it isn't an action valid? I hope I'm being clear with the question.
Thanks!