In reply to tomjbennett1:
Easy to meet people out there, not always easy to tell if they know what they are doing or talking about.
Personally I would avoid Petite Verte area if solo as it is a wet glacier with plenty of slots to fall into if you don't know what you are doing.
From Chamonix head up ( walk or train ) to Montenvers and get onto the dry Mer de Glace. Does involve down climbing some steepish ladders but you could protect yourself with via ferrata kit if required. Great place to hone crampon, axe, ice screw skills. If with others you can also set up top rope climbing on steeper sections further up the glacier. Great walk up glacier - perhaps visit the Couvercle or Envers huts - again as long as you are comfortable with ladders.
The Aiguilles Rouges gives great snow practice, especially making snow anchors. Also several easier routes to walk / scramble / climb above the Lac Blanc and Index areas. I believe Mont Buet is good too, never done it myself. Perhaps buy 'easy ascents in the Mont Blancrange' by Burnier and Potard.