I went to France about 6 months ago to get a sub script. Doctor visit was free, she was incredibly cool, prescribed me more than the maximum amount she was supposed to and threw in 60 10mg valium as well to sweeten the deal

I left the pharmacy with 1.6
grams of buprenorphine, valium, methadone capsules and a huge smile on my face.
This was the south of France. Beautiful place. Speaking French will help you greatly in getting your DOC. As was already said you can get a few varieties of codeine tablets OTC, as well as one with ethylmorphine. Diphenhydramine, and some mild muscle relaxant was also available. Cant remember the name though. Syringes through needle exchanges, pharmacies or vending machines that accept tokens

I noticed that there was no citric sachet in the box which I thought was strange as their gear should be the same as ours, ie brown, made for smoking. I later realised that there is basically no heroin in France. Paris and the north it is supposedly more available but quality is meant to be very bad. People shoot subs, methadone, coke, morphine.
Skennan morphine capsules are available, look around methadone centres, prices very reasonable. Coke down there was very good. Weed/hash easily available. Not sure about E/speed but im sure it wouldnt be hard to get in the right place. There were a lot of younger guys trying to scam you around train stations but the scams were easily avoided and pretty harmless.
The main obstacle in trying to score gear from addicts was the language barrier.