Category tree, is it worth it?

I need some insight on how to design my database regarding categories.

My site allows the users to post several different types of things for example, recipes, articles, products etc and there will be "category trees".

What I'm wondering is, is it really worth it? For the first year or so, I will be using at most 30 categories, so I could do it all by "hand" without the need to make a complex database structure/table that works as a "tree", wasting a lot of time implementing, when I could just make a table "categories" each one with an id and write some server-side functions to fetch the category needed.

I'm trying to save as much time as I can with this project, so that's why I'm wondering if its really necessary.

Thanks for helping me out.