I'm looking for a job that I can take up when summerschool ends.
I worked a lot over the summer during high school and I found that most of the time companies aren't looking to hire for only a month or two. What I did is I started working over the summer but continued to work during the school year (Just some days after school and some weekends)- I think people are much more likely to hire you if they can keep you around for a little while. It makes sense, as my training for my job in high school took a little over a month and after they had spent that long training me they didn't want me to just leave!
As for looking to apply places, try to narrow down what kind of job you would want to have! I worked in retail, but many small food or pastry shops are also willing to hire people under 18. I recommend looking at smaller shops (not nationwide chains) because I've found they're often more willing to give jobs to teenagers, especially if you know the owner/someone that works there!
I hope this helped,