Hi Meier,
I've been able to find a few external back links going to pages that no longer exist on your website. I would recommend redirecting the old pages to the closest existing pages to recover that "link juice". If you had any internal links going to the old page, change that link to the new page that it will be redirected to.
When the links being followed begin to land people on the new pages the 404 errors will no longer be seen.
I hope this helps! Let me know if you need any more detailed information.
Be well,
Alex Brown
Del Mar Fans & Lighting