It has been stated that “145 lb. person can burn 300 calories in 30 minutes on an elliptical”. The elliptical is better on your joints. I’d recommend not skimping because cheap elliptical lack features and can often be noisy (clunky or squeaky) and that will turn you off of using it
Here is a short video to explain how to use elliptical trainer
Here is a chart you should keep in mind before start