If you book a plane ticket with your credit card, many offer travel and basic health insurance already included with your credit card (check the terms and conditions of your credit card providers to see the details)
If your credit card does not provide travel health insurance, you may want to get a temporary policy which will cover you while traveling
If you sign up for Revolut (see the section FAQ section about money), they offer a pretty decent travel insurance if you sign up for one of their higher level offers
Healthcare is relatively cheap in France:
25€ to see a non-specialized doctor
100ish to see a specialist
Can be pricey if you need to be hospitalized (this varies a lot if you go to a public or private hospital), but nowhere near the prices in the US
If you need a doctor:
You can book a doctor near you or on video conference through this link.
In Paris, there is a service called SOS Médecin which can send a doctor to home / your hotel room 24/7. A consultation is about 80€.
France/Europe use a different electrical plug than in the USA, so make sure to buy some adapters (here or here on Amazon) before you arrive. This article has a ton of information about the subject.
The power outlets deliver 230v instead 115v in america. Before bringing / plugging anything in, check on the label if a least a voltage of 230v is supported.
Usually things like phone and computer chargers work in Europe. It's trickier for appliances like hair driers, baby bottle warmers, and electric toothbrush chargers.
If you're planning to travel in Europe, the plugs and the voltage are more or less the same in every country so one adapter will work everywhere on the contient (except in the UK which has very weird plugs).
Guns are totally illegal in France. Don't bring any. Even larger knives can be considered a weapon and seized the border.
Marijuana and other drugs
Marijuana and other drugs are illegal in France.
Do not bring marijuana in any forms (gummies, vape pen, etc.)!
Smoking cigarettes is legal (but very expensive).
Drinking is legal starting at 18 y/o. It is very rare for someone who looks above 15 to be asked to show an ID card when ordering a drink.