It is best to learn calligraphy first and then to learn calligraphy. I don't agree with interspersed learning. Gao Shen is a good post for learning facial and body strokes. It is recommended to learn Gao Shen first, but I personally feel that Gao Shen's horizontal drawing is difficult to master and it is easy to write in vain. Yan Qinli's style is close to Gaoshen's and can be learned together with Gaoshen's. Then I suggested switching to Magu Bei. Magu Bei is very good for practicing writing power and structure. Duobao Pagoda is an early work by Yan Zhenqing. I personally think it can be seen but not learned.