Advice to store my luggage in Paris ?
 

Hello, my wife and I plan to travel in Paris in september. We are renting an airbnb in the Marais from 3pm but our flight arrives at 10am.
Is that possible to store our luggage in any place before the check-in ?

Major train stations in Paris have left-luggage facilities, called "consignes." The most convenient ones for OP are at the Gare du Nord and the Gare de Lyon. From CDG, you can take the RER train directly to Gare de Nord, or you can take the Air France bus ("Cars Air France") directly to Gare de Lyon.

Hi !
It is also often possible to drop your bags at the Airbnb location before the actual checkin time if you ask your host kindly ;)
Done that multiple times!
Cheers,
Ben

If you need to use a locker in the Marais area. There's actually a City-Locker that provides prepaid lockers at this address: 83 rue des Gravilliers. Cheers

You should contact your host and ask if they have any suggestions. Depending on when previous guests are leaving (or if no one was there the night before) they'll tell you to drop them at apt. Or they probably know most convenient place to store them nearby.

I called my host and he talked to me about a service of a mobile luggage storage in Paris.
Have you heard about them ?

Thanks @MmePerdu

I see the website and it's seems good

what do you think ?

I think it's a great convenience if the price isn't a deterrent. Left luggage facilities at train stations are an option, of course, but making the trek to retrieve your things, depending on where you are and where you're going at the time, can be a pain. And the biggest pain can be a sometimes long & time consuming line to leave or collect or both. So this addresses all the problems of a fixed location service. If you decide to try it, please do come back and tell us how it worked for you. Kind of a great idea if managed well.

So I called the company and booked the pick-up our luggage at the airport and they file them before my airbnb rental with a concierge. The service seems good.