Behind the “Place des Terreaux” Rue Ste Catherine, weekend nights are the worst as there are a few pubs and people roaming the streets. The police do patrol the area.
Metro. Part-Dieu station near the main train station. People try to sell you false train tickets. Use the machines they are safer and probably more reliable.
Rue de la République or outside Part-Dieu station, People advertise for Charities and ask people to donate to false charities. Obviously some are real. Homeless people might try and sell you newspapers, only buy from them if they have an ID card issued by the editors.