I’m interested in getting into speedrunning (specifically Mario Kart 8 for the Wii U) but I have no idea how to go about it. Anyone got any tips?

hello and welcome!

Pick a category, read the rules for the category, record yourself playing with either a camera on the screen or a capture card, upload the video somewhere, then submit.

https://www.speedrun.com/mk8?h=32_Tracks-150cc&x=xd1m7rd8-ylpm6vlg.p12z6d1x