Hey rainn,
I've been in a similar boat with an old laptop before. Besides cleaning up files, you might want to consider upgrading the RAM if possible. It's usually a cost-effective way to give your laptop a speed boost. Also, switching to an SSD if you haven't already can make a world of difference in performance.
As for software tweaks, disabling unnecessary startup programs can help speed up boot times. You can also try using a lightweight browser like Firefox or Opera instead of Chrome. Lastly, make sure your laptop's drivers and operating system are up to date. These small changes can sometimes add up to a noticeable improvement. Good luck! 😊