I'm new to minecraft and watched many videos on YouTube and the thing that most fascinated me is that players got the same block that they were looking at in their hands in creative. Can I do this on Xbox?
Yes, you can
This can be done through the use of pick block, which is usually bound to middle click on PC editions (Win10, Java). It is not bound to a button by default on xbox, so requires setting in Settings.
Once you have bound it to a button, then when you look at a block in creative (let's say blackstone), you will be holding the block in your hand.