How to lose weight in a month?

So i have an animecon in a month and i want to cosplay, but therefore i have to wear a miniskirt. I dont think im too fat, but i just want my thighs and legs to become thinner so i look decent. how can i effectively lose weight in a month time? I dont want to waste any money sice i''m poor lol, and i cant go to the gym or whatsoever.

Three Reasons Why You Should Lose Weight

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if u wanna lose weight but dont hurt yourself a lot i got some tips that i figured through my long termed diet and that way u can eat more! 
Drink a lot of water 
DON''T eat any food for 3hours after u exercise 
dont take cold showers after exercising tht will stop ur metabolism 
eat a lot of vegetable and fruit before main food so u wont be hungry and u will eat less 
2glasses of water after each meal 
dont eat food for an hour before u sleep 
im a 15 year old girl and im on a diet,all that stuff i told u work
also exercise
dont eat junk food and chocolate and pizza and soda
visit bodybuilding.com

• You don''t need to go to the gym to lose weight. There''s fitness videos, running/jogging, jumping rope etc. I lost 55 lbs and never step foot in a gym. I do cardio and strength train in my own living room.
  
  Figure out how many calories you need daily to maintain your current weight and then subtract 500 cals. That''s the amount you should eat to lose weight.
• Ok now I don''t want to be a pain but poor is an attitide and broke is just for a while.