How can I make some money?

I spent so much money in London last week. I was over for the Wimbledon semi's and spent probably £250 within 3 days.
All of that money was just given to me by relatives (and parents), and they didn't expect me to spend a large majority.

I'm going to Spain on Friday, which is the day of the WC final (Spain are through!). So I'm hoping for a sick ass week.
But I have barely any money rn, and I don't want to ask for any because I got a lot for London.

This isn't just for holidays; I need it for nights out too. I'M SO FUCKING BROKE.
I'm doing lifeguard training next month, so I guess there's that. Any other suggestions?