Do you have a back pain? If so, start strengthening the opposite muscle, the abdominals, which will help with muscle balance. Once you ab muscles get stronger, your back pain will go away.
1. Start with bracing your core when you sit or stand. A good suggestion is to sit on a ball which forces you to do this.
2. Next, add planks, regular and side planks on the elbow which emphasize the core muscles more.
3. Later, add rotations to your plank and standing torso rotations with a medicine ball.
4. In addition add kettle bell swings which really help those muscles because of the odd shape of the weight.
5. Try TRX. Every move you do forces you to squeeze your core.
6. Once your core is rock solid you will be able to add heavy weight lifting which is one of my passions.
I will be happy to help you achieve all the goals in your journey!