In France, a wide variety of statuses are available to you, each with its advantages and disadvantages, there is no ideal status but we can focus on the 2 most used statuses:

SASU for Société par Actions Simplifiée Unipersonnelle: it is the simplest and most flexible form of company. Your SASU is an independent legal entity with which you will be able to invoice your services. The statutes are simple and flexible, but you will have to manage all your accounting and tax obligations either by taking a physical accounting firm or by using an online solution such as wity.com or dougs.fr, which are cheaper solutions but will require more time.
Wage portability: This is the turnkey solution for starting as a self-employed person.  You decide the price of your service and the wage carrier will issue the corresponding invoice at the end of the month. She will pay you directly via a pay slip. This way, you keep all the benefits of salaried employment such as social security or unemployment benefit if your mission stops. We have selected for you www.webportage.com the 100% online offer!
Self-entrepreneur: With nearly 1.2 million self-entrepreneurs in business, the status is attractive both for a complementary activity and for a full-time job. This ultra simple system will be suitable for a business launch without the need for an accountant or VAT return, up to 70,000 euros of revenue excluding VAT. This will allow you to focus on the essential, your future mission! Moreover, the SHINE application allows you to open an account and get started quickly.