Give here your best advices to settle in Switzerland

Hello everyone, I have the project to live in Switzerland in the area of Genève. I have been there for a short week and I have really appreciatied the area of Lausanne. I have a job offer in Genève and I want to know if it easy to meet people there, make some new friends especially for thirty-something foreigners. Please can you give here your best advices to settle in switzerland, in Genève or Lausanne? where to find roomates to share appartments, where to make new friends, where to find advices for administration purposes, where to find good food? But the most important is to tell me what is your feeling about switzerland ? How long have you been there? Will you advise some one to go live in switzerland for many years or for the whole life? ( I'm french, I have already lived in Luxembourg, It was not particularly cool, so I don"t know if switzerland is better)