I am new to Riviera, but not new to solo travelling. I have found that travelling in an escorted group is a very safe way to travel, and there is always the Tour Manager to turn to in case of problems or in need of ideas. I have never had an evening meal alone, but have had one or two solo lunches, which was my choice at the time. Where you go is entirely up to you. Interests, budget, departure airport, and length of holiday can all play a part. Don't worry about age - it is only a number and is rarely of concern as long as you are reasonably mobile.
Hope this helps.