transportation from Gare du Nord?

There will be plenty of taxis, but they may be very expensive. Or you can take the metro. Download the Bonjour RATP app for metro/bus info.

Take a taxi. The 7th isn't well served by the Métro from the Gare du Nord, especially if you'll have luggage.

There will be plenty of taxis at the station. Make sure you get in the line for official Taxi Parisiens, and don't accept any offers of rides before you get there. The taxi should run the meter. If the driver says it's a flat rate, get out and get another taxi.

Taxi. By all means get in the taxi rank. It is to the right near the front of the station, after you exit the train platforms. There will be signs, but look right. It is so much easier taking a taxi to your hotel when you have luggage. I'd also suggest you download the G7 App incase you want a taxi at any other point. It's so easy and efficient to use. I ordered my return taxi to Gare du Nord through it. Easy, Peasy.

Be very careful. Gare du Nord attracts taxi scammers because it’s where so many foreigners arrive. Do not follow anyone out of the taxi rank. Take only the taxi that is offered when you get to the head of the line. Look to be sure the meter is at 0. Hold up your Google maps to show the driver the name of the hotel.
Everywhere else in Paris is ok but you need to be careful at Gare du Nord.

The taxi meter will start at about 7€ which is the minimum fare. Just make sure the driver starts the meter, there are no fixed fares. Taxi rates are explained in English found on a sticker placed on the left rear window.

Go to the official taxi rank. There may be a line. Be patient. It moves quickly

If anyone comes up to you to offer a taxi, ignore them. They are scammers.

Thank you to all for the guidance!