nandohyphen1 I would like to install Linux on a Windows computer but I heard that on September 11th, Windows made it so secure boot cannot be disabled.
Neither Windows nor Microsoft as a company can change whether Secure Boot can be disabled or not. It is only your hardware vendor that can decide that, and only through BIOS/UEFI updates you have to install manually, and they would never change that for existing models anyway, because disabling certain features with updates may break consumer laws in several countries.
Whatever you heard is simply not true. It isn't even technically possible.
nandohyphen1 I just realized that about secure boot so I need to be 100% positively sure its going to work, since I can't afford to buy a new computer if it goes wrong.
If Secure Boot does not allow you to run Linux, you won't even be able to start the installation ISO for the Linux distribution in question, so your Windows installation will remain in that case. If you can start the installation, it will work. In case anything goes wrong, you will of course always be able to install back Windows again. You can download the installation ISO from Microsoft's website.
nandohyphen1 I can enter the BIOS and see that secure boot is enabled. Using the up and down arrows doesn't move the selector up or down, so I cannot select secure boot to disable it. Does this mean it cannot be disabled and/or Linux cannot be installed?
If there is an option, you will likely be able to change it to disabled. Usually you use up/down arrows to select the option, then Enter to open the menu of available options, and then select among those. Set it to disabled.
Ideally, one would install Linux with Secure Boot enabled to provide full verified boot similar to what GrapheneOS has, but there is no Linux distribution out there to date that implements full verified boot, so it is okay to leave it as disabled.
nandohyphen1 Does going into the BIOS wipe the computer at all?
No. You can even change Secure Boot state and what boot keys are enrolled without causing anything to get wiped. That is downside actually, since it makes it hard to implement Anti-Evil Maid protections properly, meaning even if Linux did implement full verified boot properly (they don't), it still wouldn't be as secure as on GrapheneOS. But in your case it means you don't have to worry about anything getting wiped. Unless you click that option to do "Secure Erase" to "optimize NVME/SSD performance". That wipes everything.