Deleting old files on my new MacBookAir

Optimize storage space on your Mac - Apple Support offers some suggestions.

I do not recommend anything other than a methodical approach. It took 20+ years to accumulate those files, so let it take time to review what you don't need. You are likely to find many files don't occupy much space, and can be ignored as inert. Larger wasters of space are easily identified in that Optimize document.

tbirdvet wrote:

Keep a good TM backup and if you later on you determine you should not have deleted you can always restore.

👍

Two or more TM backups are an even better idea.

All depends how important they are. You can list your files by date and then highlight the real old ones and then delete all. Otherwise you would need to review what is important or not and selectively delete. Keep a good TM backup and if you later on you determine you should not have deleted you can always restore.