HELP...... Defining Short term goals!!!!!!

hello everyone,
I'm new here....still trying to figure out the website and how it can help me.....

my Current weight is 75 kgs approx... :embarassed:
and my main goal is to be 55 kgs atleast.... :drinker:

But thats my long term goal... but i don't know how i should divide it into various short term goals or little milestones....

On what basis should i do that and losing how much is considered healthy per week/ month?

please help me define my short term goals...