I teach a very gentle form of yoga that is good for older people, children and first-timers. You're never too old to start and you may be surprised at the rejuvenating effects o the practice once you get into it.
You can never do too little in yoga. You can do too much and injur yourself butyou can never do too little. So if something doesn't feel right, or if you just don't feel like doing something - leave it out.
I used to work on buildings, now I work on bodies. I traded steel and concrete for muscles and bones. It's much more fun. I teach yoga and I design home-offices.