Visa Hungary, then go to France from Hungary. Do you want to buy a round trip ticket?

No need. According to the regulations among European countries, visitors with Hungarian tourist visas can enter and leave other countries in Schengen area at will after arriving in Hungary, including France. Therefore, when you have a Hungarian tourist visa and plan to travel to other Schengen countries, you don't need to buy a round-trip ticket, you can arrange a one-way ticket, from Hungary to France and travel freely in Schengen District.