301 redirects from old website--Best Approach?

I have a number of urls from my old site that I want to direct to completely new urls... I'm kind lost. Reviewed Routing but... not sure where to put

pages: redirect_default_route: false redirect_default_code: 302 redirect_trailing_slash: true
or

redirects:
/jungle: '/blog/the-urban-jungle[303]'

Ok. The redirect goes in the site.yaml and I got that working.
redirects:
/joys/creating-a-household-notebook/everyday/205-its-okay-to-let-go-of-old-greeting-cards-really-it-is: '/organize/its-okay-to-let-go-of-old-greeting-cards-really-it-is[301]'

But something curious is going on with the Simple Aliases
when adding this to my site.yaml
routes:
/joys/creating-a-household-notebook/everyday/205-its-okay-to-let-go-of-old-greeting-cards-really-it-is: '/organize/its-okay-to-let-go-of-old-greeting-cards-really-it-is'

The page displayed but the content was duplicated in the footer...

You can do it with the administration panel>Pages>Editor(advanced)> ->Route Overrides. Your settings:
default route: /your-new-page
canonical route: /your-new-page
route alias: /your-old-page-1
route alias: /your-old-page-2
Now you have 3 names of the page (double content). You can redirect all aliases to the default route with
Redirect default route: yes
In the default.md of the page it looks like this.
redirect_default_route: true
routes:
default: /your-new-page
canonical: /your-new-page
aliases:

• /your-old-page-1
• /your-old-page-2
  The other way is to do it with the Configuration (Site)->Redirects and Routes. Hope it helps.