Brand New At This

I would like to either water-fast or juice-fast as a means to cleanse and lose weight. I know absolutely NOTHING about this practice with the exception that the goal is to start ketosis, breaking the fast with protein is "bad," and breaking the fast must be done a certain way.

First question is: which fasting approach is preferred for cleansing and weight loss, why, and how often?

Second question is: how long does an initial fast run?

Third: when does ketosis typically kick in, and how do I know that it has?

Fourth: how much water/juice should be taken, each cay?

Fifth: how is either fast broken?

Brightest blessings!