visiting China but fly to HK first

You just need to apply for a single entry L type. If you can ask your friend to send you an invitation letter and copies of his passport information and visa pages (if he is a foreigner) or his/her Chinese ID card (if he/she is a Chinese), then you needn't provide round-trip air tickets and hotel reservation in China. The application should be submitted to the CVASC branch in your area.