Your familiar cannot attack by themselves, it’s true, but they can float around a front-line character and grant them advantage on an attack each turn! The only risk in using your familiar in this manner is that it paints them as a target for the enemy. In past editions, this could be a detrimental risk to the caster.
What can a familiar help with?
Yes, familiar can be used for gaining advantage for allies. Your familiar acts independently of you, but it always obeys your commands. In combat, it rolls its own initiative and acts on its own turn. A familiar can’t attack, but it can take other actions as normal.
What can a familiar of find familiar do?
A familiar can’t attack, but it can take non-attack actions, including Help. As the text of the Help action indicates (PH, 192), the action doesn’t require you to be able to attack; you simply need to be able to provide some sort of distraction. Does the familiar of find familiar count as an ally for the purposes of Sneak Attack?
When to have your familiar hold its help action?
Easy work around, have your familiar hold its help action until your turn. Or ask your DM if you can just have the familiar go on your turn. Sometimes it is easier for the DM if you have your familiar move with you.
When to use familiar and help action for advantage?
It would delay action to help when it looks like your character is about to attack. That’s another possible way to play it, good thought. Just have to be careful of AoE spells. This works with every familiar, and not just the owl. However, the advantage of the owl is the flyby which removes it from melee after using the help.
What kind of action can a familiar take?
As far as actions in combat are concerned, the quote you’ve included pretty much sums it up. A familiar can take any action that it is capable of other than the Attack action. This includes the Cast A Spell action, Dash, Disengage, Dodge, Help, Hide, Ready, Search, and Use an Object.
