The earliest Sonlight recommends starting any sort of formal curriculum at all is 3 years of age. At that point, you might want to consider our P3/4 program (http://www.sonlight.com/TMSP.html).
For now, I would suggest spending lots of time playing with your child. God made young children so that they learn best through play. A wise friend of mine once wrote: "For kids, play is work! I think if adults would realize that, we would not try to rush and ruin the built in educational system that God has designed for little children. They are inquisitive, they ask questions, when they are ready to know something they try to do it, or ask about it, they learn quickly. And they play."