Problem with local multisite setup

These are the instructions for creating a multisite network, which involve more than editing the options table.
https://codex.www.ads-software.com/Create_A_Network

This article might help, since on localhost, there are some differences from a live host:
https://wpdreamer.com/2013/08/how-to-setup-a-localhost-wordpress-sub-domain-multisite-environment/

Thanks. I wanted to use the multisite feature for a multilingual website, but it seems that this is not really a good a idea, because the website is just for a small business.

Multisite can be a helpful way to set up multilingual sites. Multisites is more complicated than single site WP however, so you will want to look at the skills required to create and manage a multisite network before diving in.

You might find this article about setting up a multilingual network helpful.

But for small business websites it’s overkill, isn’t it?

Generally, yes. ??