So I was looking to start Speedruning this game, but first I would like too know where to get a GBA linking cable and a capture card for the wii

I would recommend looking at ebay or amazon for these things. And depending on the category a link cable for tuner may not be needed.

I was thinking trying different categorys and seeing which one I liked the best

So I might need a tuner

The categorys I wanted to learn are all dungeons and hundo just fyi

ebay is usually fine for GBA and link cable, capture card there's a bunch of different options but a good relatively cheap one is a gv-usb2. but also I would recommend trying out some runs before you get these things to see if you actually enjoy the game, especially the GBA and link cable because they can be quite expensive and are basically useless outside of running the game

What do they look like or a link to a linking cable so if I decide to run this game I can look at it I already have a GBA btw