I never know where to start where I get a calculation question given many values, what should I do? (e.g: finding how much energy is needed for all the ice in a glass of water to melt after the ice is dropped into warm water)

Firstly, you should always list down the values that were given to you in the question so that you know exactly what you already know, and then by looking at this list, it makes it easier for you to remember what formula to apply. Then, if applicable, try to sketch a diagram of what is going on. For example, if the question was related to forces acting on an object, a force diagram with arrows would be useful; or in the example given above, drawing a temperature vs time/phase diagram would be useful to see when is the energy going into changing phase and when is it going into increasing the temperature. Then, with the list of values and a diagram, you can match the values that you have to the diagram, and thus see what you need to find in order to solve the question.