PLEASE HELP

Okay so this isn't really related to this app but me and my friend planned a house party from 8-11 and we'd stay at our house until 9 and move the party into the woods...I asked my mum and she said no and we're really wondering what to do? Any ideas? Hiring halls and places will be too expensive. (No hate please I don't want advice saying how we shouldn't have it I just want ideas)