Can’t install Big Sur

Hi,

I’m unable to update to Big Sur on my MacBook Air. I was previously on Catalina but my Mac was full of useless files so I decided to wipe it and start from scratch. Cleared everything including the OS and it would only allow me to install Yosemite when I rebooted. Figured I could update to newest MacOS when I had it set up but it’s not available in system updates and when I try to install from App Store it gets stuck and doesn’t fully install. I’ve wiped and reinstalled 10000 times and can’t seem to do it. Can’t use my laptop on Yosemite as it isn’t compatible with anything due to being so old. How can I install Big Sur?