Could you please tell me if we can do the visa on arrival in Da Nang, or we have to do in Ho Chi Min City?
Thanks for your question!
Based on your itinerary, you will get visa stamp at HCM airport then can fly to Danang
And French passport holders do not need visa if staying in Vietnam within 15 days. However, the previous visit must be far from the next one at least 30 days. In addition, the passport must be valid at least 6 months
In case you stay longer, you can apply visa on arrival at this link: https://www.vietnam-evisa.org/apply-visa.html