My wife and I will be flying into CDG Paris on april 23rd. We fly in Delta (from the US and out Air France to Sevilla, Spain. These were two separate bookings. Wondering how we transfer in the airport. I assume we pick up our bags from the Delta baggage claim and then check them in with Air France. Does this mean we go in and out of a secure area? I assume we go through immigration as if we were staying in country. Never been to France so not sure what to expect. Looking for a little guidance.

Thanks.

You must go through immigration control and then check your bags for the second flight. French customs is also required but usually is a walk-through. There likely will also be a security check to board the second flight. No border immigration in Spain as the French procedure covers both countries.
This sounds like a home-made itinerary. If you had booked the flights on a single ticket, at least some of the bother would be reduced and more of the responsibility for completing the connection would be shared with the airlines. And it might be cheaper.

Yes, it was booked separate. My son is a Delta pilot so we fly free with Delta. The flight into CDG was free (only taxes) but we had to pay for the flight from CDG to Seville. Thanks for the information.