You could get into a muscle strength/endurance regimen but will have to do it under the guidance of a certified trainer to minimise the risk of injury.
Your other option could be to do some free hand exercises by yourself, like push-ups, for the upper body; squats for the lower body and some abdominal crunches and back extensions for the midbody. You can also do some shoulder, tricep and bicep work with light weights to start off with and to get the body accustomed to the routine. But I would suggest that the initial stages be supervised.