Can a unit card draw resources from itself if it has resource values?

You can focus units with the resource icon to pay for cards, like you can from objectives.

I am unfamiliar with the term "draw resources from itself" but I´m guessing this is what you meant?

No. Some unit cards have resources on them. Lets say I want to attack with that resource card. Can I place a focus token on the same card to be able to use it since it has a resource value?

I think I figured it out though. If you put a focus token on a card it becomes exhausted which means you can't use it. So, the answer is NO you cannot generate resources from from the same card.......I think.

You cannot use it to attack and for the resource. One or the other.

What you can do is enter a unit that generates resources into a battle, and before it strikes (in an action window) use its resources, so long as it is ready.