looking for advice from single dads please, (Paris)

regarding French law on access to my son who is Swiss, and has just moved to France from Austria with his mum.
I am wondering what the laws on fathers access are there, and who is in charge of deciding it when mum and dad dont agree.
the Jugendamt in Austria were in charge, since he was resident there, so I assume the French are now?
kind regards
Nigel
ps. He is 14 now, his mum and I were not married, but lived together for 8 years in Austria. I am a Brit. She has sole obsorgrecht , or did in Austrian law.