Apply for some... No one will knock on your door and offer you one!
Go for service industry jobs... peak demand and people always want to take holidays. Try supermarkets (good for ongoing opportunity also), cafes, juice bars etc.
Restaurants have a high turnover rate and thus frequently have openings. Department stores are good places to work and always seem to be hiring.
Apply at the place you want. Show up and introduce yourself. Keep showing as often as you can until they're so sick of you that they'll hire you!!! Or at least recommend you to others as a persistent individual. Good luck.
Take it seriously. Go for it. Check out restaurant jobs . Ask full time. Get with a large company. You're at the beginning so pay strict attention and plan on working hard to establish a good reputation. Plan on saving your money for a car or school.
Invent time travel and go back to 1998.
Pray for the summer.
The longer and the hotter, the better.