"*If I have just carry on suitcase, will I have to go through luggage security before boarding the final flight? *"
Yes, absolutely you will go thru Security in 2F and then go thru passport control AFTER security. I agree with Andrew.
Follow the signs overhead saying "Correspondence" and 2F. Do NOT follow the crowd as they will be going to Paris arrival immigration and yours will be in a different place.
I'll add that you can speed things up by having your liquids in a quart ziplock bag. They will insist on this and when I went thru last year the guy at the beginning of the security belt had a handful of quart/liter baggies that he was handing out to people. I had my liquids out, held up the bag and he just smiled and gave me a nod. The lady ahead of me was fumbling to reassemble and throw away her liquids that didn't meet the 3oz/100ml size guideline (had an OJ and yogurt in her purse!). The security guy just looked at me and rolled his eyes. Have the liquids bag handy either in your personal item or if in your carry on, have it by the zippers so you can remove it easily.
BTW, even if you check the bag, you'll want to have anything liquid in your purse (toothpaste? hand sanitizer? chapstick - yes, they counted this as a liquid when I went thru) in a ziplock.
My experience was in October 2022. I do not know if they've since installed the kind of xray scanners that mean you don't have to take liquids out or not. I think not as someone was just ranting on a FB group I'm in that they made her put everything in a ziplock when she had it in one of those clear plastic bags sold that say "TSA compliant". I timed how long it took me to walk from my Seattle flight which parked at a tarmac location so had to bus to the main area to my gate on 2F and it was 1hr5minutes. I did not run. I walked moderately. I'd never done a transit there but I'd arrived there many times and kind of knew where the route was to 2F.
How long do you have for your transit? I'd also look to see what the next Air France flight is to Nice in case you are delayed. There are multiple flights a day from Paris to Nice so they will get you there even if you miss the flight you are scheduled on. I'd also go to the toilet on the plane about an hour and 15 minutes before you land. They will start a food service about an hour out so get up and go before the aisles are blocked. Then you can make it to the Nice plane without needing a pit stop.