I would start with walking because it is something that you can do with your little one. If you get out for a 30 minute walk about 5 times a week, this would probably make a big impact when combined with primal eating. Once you start to shed some weight and become stronger, you could start to run while pushing your toddler in a stroller. Then once you get back to the house, do a couple of targeted excerises like push ups, ab crunches and squats.
Hiking is also an option, but you'll have to make sure that you've got a good baby carrier for that. I use a Bjorn and they work great. Also, be careful to avoid extreme elevation hikes that require you to do any kind of mountain climbing type movements because this would be unsafe for your little one.