Learn Croatian: Možeš skrenuti desno.

In Croatian, the verb itself usually tells you who is doing the action. Možeš specifically means "you can" (informal singular). You don't need to add the pronoun ti ("you") unless you really want to emphasize who you are talking to.

Why does skrenuti end in -ti here?

The ending -ti shows that skrenuti is in the dictionary form, called the infinitive (meaning "to turn"). Just like in English, when you use a modal verb like možeš ("you can"), the second verb stays in its base form.

Where does the word možeš come from?

It is the "you" form of the verb moći (can / to be able to). Moći is an irregular verb, which is why the "ć" changes to "ž" in its present tense forms like možeš.

Does the word desno change endings depending on who I am talking to?

No. In this sentence, desno ("to the right") is acting as an adverb because it tells you where to turn. Since adverbs describe actions and not people or objects, it will always stay as desno.