How can I make money easily?

Yo I'm 13 and I really want to get some money to get my girlfriend something she really wants (she doesn't know I'm planning to get it). I used to get money a lot but my dad and mom can't do that anymore. I did ask but my dad thinks that if I want to get it for her I have to earn the money by doing jobs for people. I really need help I appriciate any answer thanks for your intrested

Try mowing the lawn/washing cars for ppl in your neighbourhood, newspaper delivery, walking ppls dogs, things like that.
Ur a nice boyfriend, shes lucky to have you.