Taxonomy is not right for you if:
You don't know ExpressionEngine very well.
If you've installed EE for the first time yesterday, it probably means that you shouldn't be dicking with third party addons right now. Go read the manual, understand how EE is primarily a dynamic system that breaks away from the 'pages' concept, and come back when you know you require a section or sections of your site to run off static, hierarchical content. And/or if you need your client to be able to edit certain menus around the site.
Your client is an asshat
You get quite a lot of control with this module, if you handover to a client that likes to fiddle where they shouldn't fiddle, Taxonomy is probably not a great choice for your project.
You don't like free or open source software. Weirdo.
Your site has 3 pages.
C'mon, you really need a module to build a menu for 3 pages?