Using an SEO plugin does not mean that you have to be locked into using that plugin on your site. You can easily migrate SEO plugin data between plugins.
Once you have the Rank Math SEO plugin, go to the settings in wp-admin:
Rank Math SEO > Status & Tools > Import & Export
You can create a backup of the site SEO settings before you run the import of the data from the Yoast SEO plugin into Rank Math SEO.
If you are migrating data to the SEOPress plugin, then from wp-admin go to:
SEO > Tools > Plugins
From the plugin drop-down list, select the Yoast SEO plugin. Then you will need to click on the Migrate Now button.
You should only have one SEO plugin active on your site. Otherwise, this can cause plugin conflicts and other issues.
Changing the SEO plugin is not as complex as you would expect and you do not have to stay locked into using a specific SEO plugin on your site. Following the steps in this help article should make it easy to be able to migrate SEO data between plugins on your site.