Mandarin Club hosts weekly calligraphy classes in their Chengdu classroom which I had heard about for a while. I went last week and it was great, so I recommend that anyone with even a passing interest in calligraphy checks it out. You can attend a trial class for free and if you decide to continue the price is 500 yuan for 5 weeks which is very reasonable!
There’s an experienced teacher who leads the calligraphy lesson and it’s open to all skill levels. They provide everything, all you need to do is show up.