First you should know that studying is practice. The proper attitude and concentration with which one studies should not be neglected. As far as Mahayana sutras are concerned I can give no advice. Because I started with Lamrim, listened to teachers, studied commentaries about sutra and tantra and then re-turned to the Lamrim and - in addition - turned to the sutta pitaka. The sutta pitaka has been completely obscure to me in the beginning but I feel that this has changed after my voyage.
As far as I have known, there's are Sutras read and studied in Ch'an but in Zen, which normally is associated with the Japanese Buddhist Tradition and its affiliates, they may have a different approach and one place I know you can get sound advice would be ZFI
maitreya31 wrote:I'm searching for the Dharma . I studied the Pali Nikayas . I will search for a Zen master . What Mahayana sutras should I study before begin my practice?
I'm certainly in no position to say what you should study. The first sutra I read was the Shurangama Sutra. According to what I have read this is also the sutra that the chan master Hsuan Hua suggests to study first.
A recommended reading list at the Mountains and Rivers Order. That is for a modern American Zen community. If you want to study for Chinese, Korean or some other forms of Zen the list can change significantly.
"While teachers of the middle way, mind only, transcendent wisdom, mantra, and other schools may have their own assertions, the fulfillment of those intentions is the same. There is not a single thing that is not contained within mind." (Gampopa to Düsum Khyenpa, in "The First Karmapa", KTD Pub, p 254)
Like TMingyur said, you don't have to wait before starting to practice. In fact, the sutras are more meaningful if you are practicing and reading them at the same time. Here are some important sutras in Zen Buddhism: