For SEO, all pages should be able to be found by search engines (i.e. indexed), but if you want to hide certain pages from search engines, you can set this from your site editor.
Simply click Pages from the left menu, locate the relevant page, click the gear icon, and select “SEO”
Toggle on the “No Index” option to instruct search engines not to index the page.
Click the button to the right of ‘No Index’ to instruct search engines to not index this specific page.
Note: this will only block the specific page; you will need to select this for every page you don’t want indexed.