Resistance exercise is good for building muscle. Muscle burns more calories while resting than fat does, so the more muscle you build the higher your resting metabolism will be. If you are currently losing weight while doing what you're doing then there's no need to change it just yet. It's when you hit a plateau that it's best to switch things around either by changing activities completely, doing what you're doing faster or more intensely or doing it for longer.
If you've only just started exercising it's best not to do too much too soon, otherwise you risk injury or risk learning to hate exercise so much that you eventually stop doing it entirely! What you're doing right now should be fine. Perhaps you should consider adding some hand-weights to start building a bit of muscle every second day.