Im 13 live in the UK and I NEED a job!!!?

Hi im 13 and I really need a job cuz im going to Australia wiv my school and need to pay for half of it!!!! At the moment i have my name down to do a local paper round but loads of people have put their names down too so it unlikely i will get a place until i am 70 =( I would really like to do dog sitting/walking but I do not know how to let people know tht i am interested.