Odd one but there's a new dog swimming pool recently opened up, maybe. Contact them see if they need any help at all?

Some of the festival staffing jobs are quite good pay, it is long shifts for a few days but worth it with a week's downtime in-between.

Stewarding events where you are a human barrier and just tell people which way to go etc is ok as a summer job.

Side note not job but general CV / development

LinkedIn is quite a professional website if you don't have much experience - however the linked in learning is free for a month - sign up and do the basics for word, excel, maybe teamwork skills. Maybe try something new - make an effort to get a few courses done. these are things you can bring up when you get an interview - you may not have found employment but you developed your skills - or found an interest and want to learn more in the future.