"Actually" is a word that you use when you're saying something that you think will be surprising or new information to the listeners. For example:

Wow, this is actually pretty good.

I actually did it myself.

You can use "actually" in several places in a sentence. One place is before a verb:

I actually left it at home.

Another is before an adjective:

It's actually fun.

A third is before a noun:

He's actually my brother.