I haven't played many card games either. Sometimes it does help to play lots of games in a particular genre, mainly to get a feel for how they're built and balanced, and the mechanics they use. However, it sometimes helps not to delve too much, because it generally makes your own concept more unique. In your case, you've already grabbed yourself a pretty unique concept by working 'blind', now you can get some inspiration from elsewhere to build on it :)
Best of luck with it!