I found this after the audit, there were no drastic changes on the site. Some products and categories no longer exist, but also, I see a lot of random 404 links, I don't understand why they exist. I am thinking about the best solution for this situation.
What kind of URLs are they?
random URLs don't appear out of thin air.
you mention you have products & categories, so i'm assuming that you have some kind of e-comm website.
For the products & categories, I would fancy up the 404 and let the "customer" know, those products/cat no longer exist. I wouldn't re-direct those elsewhere.
As for other ones, if it's super random URLs that should never existed, you need to find the trail of how those even came up in the audit.
Then, for more or less of them, either keep them as 404, or send it back to the homepage.
Based on the assumption previously you have a ecomm site, I would personally, keep the 404s, but finding out where that "traffic" to the 404s are coming from.
700+ random URLs which "some" that never existed before is already suspicious
