Another way you could do this - that wouldn't be sustainable to expand later - is to create two landing pages as singles in Craft CMS.

Then, create a new template for wherever you keep your header info (layout.twig usually) with all of the correct hreflang etc. in the header and include that layout template with the associated entry templates.

Give these two templates a route such as domain.com/es/slug (you should be able to do this directly in the singles setup page within the CMS).

This will create the effect you want, but without committing to a full multi-site. I emphasize again that this method does not scale well. But for an interim it should work fine. Remember to make your SEO values for these entries in the correct language.

Another way you could do this - that wouldn't be sustainable to expand later - is to create two landing pages as singles in Craft CMS.

Then, create a new template for wherever you keep your header info (layout.twig usually) with all of the correct hreflang etc. in the header and include that layout template with the associated entry templates.

Give these two templates a route such as domain.com/es/slug (you should be able to do this directly in the singles setup page within the CMS).

This will create the effect you want, but without committing to a full multi-site. I emphasize again that this method does not scale well. But for an interim it should work fine. Remember to make your SEO values for these entries in the correct language. Best of luck!