Well watch your watering. Portulacaria are succulent and can rot if watered too much. They will take a fair amount of sun. I am in Indiana and keep them outside during the summer but in dappled shade - no direct sunlight until they have been outside a few weeks. In the fall and through the winter you can keep them on a sunny windowsil or under lights. I have one sitting in my office window - it was a rescue from a big box store. It is literally glued into the pot and soil but it has been growing slowly for the past year and doing fine. I would also be careful fertilizing Portulacaria. Much like many herbs, they are used to poor soil and too much fertilizer could burn their roots. Is it green or variegated? You should post a picture with your questions - much easier to answer that way.
Good luck with your little guy,