gpio – Keyboard Matrix And Pull Up Resistors

I have a question about pull-up/pull-down resistors on the Raspberry Pi Pico.

To be as brief as possible – I am trying to create my own keyboard for the learning experience and I wanted to use the Pico as my controller. To do so I am designing a simple keyboard matrix in KiCAD.

After watching a bunch of videos and doing some reading I’ve learned about pull-up/pull down resistors (Tutorial – Custom DIY Keyboard Design and Build | Part 2: Keyboard Schematic @timestamp 26:52) and I’m confused about the implementation.

Do GPIO pins for such an application need these resistors to set the input HIGH or LOW? I know there are internal resistors but I think they’re too weak and I should be adding external ones. And how do I know if a wire would be HIGH or LOW to begin with? I read through the QMK documentation and it listed that the columns would be set as HIGH. So does that meant the columns need pull up resistors?

Any input would be appreciated/setting me straight in terms of concepts. I am a software guy and not a hardware or electical professional.

Here is what I have at the moment:

Thanks/sorry if this is not the correct place for such a post.