Learn Russian: Ты ведь наверняка знаешь этот факт.

Ведь adds the flavor of "after all" or "as you know." It shows that the speaker is appealing to shared knowledge. They aren't just stating a fact; they are reminding the listener of something they both assume is true, often to back up an argument.

Does ведь always go right after the pronoun like in Ты ведь...?

Not always. You can easily put it at the very beginning: Ведь ты наверняка знаешь... Both are very common. However, unlike the English "after all," ведь sounds unnatural at the very end of a sentence. It prefers to sit right before or right after the word it emphasizes.

What is the difference between наверняка and точно?

Both can translate to "for sure." However, наверняка is often used when making a very strong, confident assumption about something you can't technically prove (like what's in someone else's head). Точно implies strict, proven precision. Since the speaker is making an assumption about your knowledge, наверняка is the most natural choice.

Why doesn't этот факт change its ending here?

It is the direct object of the verb знаешь (you know), which means it must be in the accusative case. Because факт is an inanimate masculine noun, its accusative form looks exactly the same as its nominative (dictionary) form.