Does Spiritual Weapon use my own action to attack during combat?

Question

Does attacking with a spiritual weapon use up my own action in a turn?

The wording of spiritual weapon in the 5e handbook (page 278) is somewhat unclear to me.

You create a floating, spectral weapon within range that lasts for the duration or until you cast this spell again. When you cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon. On a hit, the target takes force damage equal to 1d8 + your spellcasting ability modifier. As a bonus action on your turn, you can move the weapon up to 20 feet and repeat the attack against a creature within 5 feet of it.

So, there are a couple points of interpretation that I'm unclear on:

1. Who makes the initial attack?

   When you cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon.

   Is that me, as in the summoning cleric, via proxy of the spiritual weapon, thus using my action for the round to do so?

2. How do subsequent attacks work?

   As a bonus action on your turn, you can move the weapon up to 20 feet and repeat the attack against a creature within 5 feet of it.

   So what's the deal here? Can I, on the next turn, use a bonus action to move the weapon 20 feet and attack as a part of the bonus action? That would leave me free to still be able to move my cleric and use another spell or take any other regular action.

Answer 1

A spiritual weapon (created by the spell of the same name) uses your bonus action for movement and attacking. It does not have its own actions, bonus actions or reactions.

The Spiritual Weapon spell has a casting time of 1 bonus action and range of 60 feet. Breaking down the spell description:

You create a floating, spectral weapon within range ...

So, you use your cleric's bonus action to cast the spell, creating the spiritual weapon within 60 feet of your cleric.

When you cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon.

If a creature is within 5 feet of where you created the spiritual weapon, as part of the same bonus action you used to cast the spell, you can attack that creature with the spiritual weapon.

As a bonus action on your turn, you can move the weapon up to 20 feet and repeat the attack against a creature within 5 feet of it.

In every round after you cast the spell, for its duration, you can use your bonus action to move the spiritual weapon up to 20 feet and attack a creature within 5 feet of the spiritual weapon.

Since any use of the spiritual weapon spends your bonus action, your cleric still has a regular action (and reaction) available.

Answer 2

The casting takes one bonus action. The description says only that you can use a bonus action to "move and repeat an attack." Otherwise the Spiritual Weapon stays in place and attacks anything within range. The description does not mention successive attacks taking bonus actions.
You can technically cast Spiritual Weapons multiple times, as it is not a concentration spell, and each weapon will make attacks, and take AoO's without using Bonus Actions, unless you move the Spiritual Weapons.