The standard mechanisms in ~TiddlyWiki for creating Table-of-Contents are macros known collectively as "toc" [[macros|Macros]] (click on link to learn more about macros). They use `Tagging` as their means of creating relationships, so be sure to review the [[Tagging]] topic tiddler if tagging is a new concept for you.
Add entries to the table of contents by creating tiddlers tagged ''~TableOfContents''. An easy way is to choose <<.icon $:/core/images/new-here-button>> ''new here'' from the tiddler toolbar of the ''~TableOfContents'' tiddler.
(if you don't see the "new here" button, click on the down arrow <<.icon $:/core/images/down-arrow>> to see more menu options.)