What to do with old site links?

Question

Google

Hello!
Dear experts, please tell us what should be done in case of change of links on the site?
More:
I had a site on a domain, of course, the pages of the site are indexed both in Yandex and Google.
But now, I completely changed the site from the old one, only the domain remained.
In this regard, a number of questions arise:
1) Will SMART Yandex index new pages if they are under a different link, but with a similar title?
2) If not, is it necessary to tell Yandex to remove old links and index new ones?
3) Or do you not need to do anything, but just highlight the search in the 404 error file?
Yandex has now indexed the site, but far from all of the pages have been displayed in the search ... And what is most interesting and incomprehensible to me, it has displayed a basket in the search (more precisely, links to once ordered materials) ...
Tell me what steps you need to follow so that both Yandex and Google begin to correctly index the site?
Thank you.

Answer 1

If I understood correctly, you changed the design and structure of the site? If so, then you just need to set up redirects from the old pages to their new equivalent and wait for the search engines to eat them at the new addresses.

Answer 2

1) Will SMART Yandex index new pages if they are under a different link, but with a similar title?

Will index, but as new pages.
Need.
Google
Yandex

3) Or do you not need to do anything, but just highlight the search in the 404 error file?

If it is not critical to lose positions in search engines or the content of the site has changed so dramatically that there is simply nowhere to redirect from old pages, then you can do it that way.

Answer 3

And here is the question:
Since there are quite a few pages, how to register a redirect for all of them? It turns out that there was a page
spkural.ru/catalog_text/95
And now it is:
spkural.ru/product/slavyanka-izolyacionnaya-tara-25kg
And so many links...
How to register a redirect?

Answer 4

Set up .htaccess file Redirect from old pages to new ones. So that traffic is not lost and search engines understand where to look for new pages.
Also update the sitemap.xml file. Yandex is actually a rather dumb system and is heavily tied to this file.