I was playing with my little brother, and during my turn he used Black Oak of Odunos's ability, paying the black mana and tapping Oreskos Sun Guide so that on his turn turn he could untap Oreskos and gain two life.
Does tapping the Oreskos Sun Guide mean that it's attacking?
No. It's the other way around: attacking with a creature requires tapping it. (Unless it has vigilance!)
If you do something else that causes a creature to be tapped, it never causes it to attack. Only actually declaring it as an attacker (during the declare attackers step in the combat phase) will do that.
If you do want to force a creature to attack, you have to do it directly, using something like Shipwreck Singer.
Tapping is a cost paid to attack. Tapping by itself doesn't make a creature attack.
Some creatures have an ability that works when you tap it (e.g. Elvish Mystic), but that doesn't cause the creature to attack.
