New to Linux arch

Hi so I’ve never used Linux and I’ve also never dove that deep into anything tech wise besides games and actual hardware. I’m deciding to go with arch so that I can actually learn how to use code at least a little bit and to learn how Linux works. My question is that I’ve heard that company’s have invested in Linux and its development so does that mean that they can just put something onto my computer or steer the updates to do certain things. I would like my devices to be mine and only me have access to what’s being put onto it. Will there be things that are hidden or outside of my ability to edit if I choose to? I’m truly new to all this and I’m genuinely interested in learning so any help or advice would be greatly appreciated.