I am new to crypto and I want to learn how to trade but I do not know where to start. Please give me some advice on what are the best exchanges where I could learn how to trade. Your advices will be highly appreciated. 
Youre not going to learn how to trade from exchanges. If youre going to an exchanger to learn how to trade then youre practically going to lose your investment , unless you happen to find an exchanger that allows new users to first create a demo account just like some forex exchangers would always do. If you want to learn cryptocurrency trading you will have to find someone to teach you that.