As the name said, the Serbian Latin alphabet is introduced and practised in Latinijada 1-4 and the Cyrillic alphabet in Ćirilijada 1-4.
You can download for free the study material from page Download [6-9]. At the end of this page there are the Solutions. How to use the study material from this site you can read in the post with that name.
On the page English/Engleski you can find more information about this material as well as in Concept of Latinijada 1-4 and Ćirilijada 1-4 and the posts written for each material separately.