Menstrual Cups

I just bought my first menstrual cup and I'm looking for some tips/tricks/insight. First of all, I have a rather heavy flow. The first few days it's not abnormal for me to bleed through 2 pads and multiple tampons... But, I got the smaller size cup. I wasn't totally sure what I should go with. I have not had any kids... I took it to mean I could really go with either one... Is that the correct assumption? And yes, I know everyone is different and every body is different t, I'm just trying to get a general idea. Also, I am still a week or two away from actually starting. Would I be able to "practice" with it now to try to find the best way to put it in, or should I wait til I actually start? Just looking for some tips... Trying to save money and help the environment a bit in one shot!