Tarpan vidhi at shahi snan

I am going to kumbh soon and would like to know what exactly to do after entering the water. 1. What mantra to say for deity (I worship maa Durga naam japa only) - do I say her mantra 11 times or 21 times in the water. 2. How to do tarpan for the deity 3. Self parikrama - turning around in place - how many times do I do it and chanting what? 3. I plan to take a dip for Ganeshji, Bhairav baba, maa durga, maa kali, my kul devta parvati, my ancestors What do I chant at each dip 4. What mudras should I do. I see online people taking water and leaving it in a particular way. Hope someone can help