What is the wattage of the blower that comes with this inflatable bounce house?

The blower included is 750W.

Can this water slide accommodate multiple children at the same time?

It can accommodate 6-10 children.

Do I need to prepare water pipes?

The package contains water pipes. If you want to have more fun, you can of turn up the water pressure in your home.

How long does it take to inflate fully?

Within two minutes

How do I store it after the party?

If you connect the water pipe to play, pour the water out of the bouncy castle and let it sun dry before storing it.