Are you regarding to making subpages from Suggestions? This can be easily done by creating a new page with your suggestion content. However, make sure you name the page with Suggestions/(your subpage content title). After you're done with editing the page, change to source editor, and paste this two lines of code at the end of the page.

[[Suggestions]]

[[Category:Fandom stuff]]

P.S. If you don't know how to change to source editor, look at the top right of your editing panel. It should say 'visual editor' at the moment. Click on it and select 'source editing'. Ignore all the codes, just paste the two lines at the end. For example, see Suggestions/Village.