Here are some suggestions:
Buy an external drive and move some of your files to it. Be sure to make backups of that drive as well as backups of your internal drive.
Move your Photos library to save space on your Mac - Apple Support
In addition to your Photos Library, you can move other image and movie files to the external drive.
You can also store some music files on an external drive.
Change where your music files are stored on Mac - Apple Support
Look in your Documents folder. Sort all the folders and files in Documents by size. You can move the larger ones to the external drive.
Learn about how to use iCloud. iCloud allows you to store some of your files only in iCloud and no longer do they take up space on your Mac when you choose that option. Some users like this, others prefer keeping physical copies on their Mac, however.
Open your user Library folder. Sort all folders by size. Look into the larger ones, there may be some files you can delete. One should always use caution when deleting items from the user Library. I saved space by deleting old iPhone backups, old iPhone iOS update downloads, and old Garmin map downloads.
If you use Adobe programs like Lightroom, you can delete many of the redundant Catalog backups that Lightroom makes.
You have a minimal Mac, just 250 GB storage. These lower-end Macs always run into storage challenges. It may make sense for you to purchase a utility like DaisyDisk, which will show you (when run as administrator) where ALL your disk space is being used. All of it. Then you can make informed decisions. In the end, when one has to buy external storage to offload files from the main drive, one hasn't really saved money by buying a Mac with such a small internal drive.
