Erased disc incorrectly now I have "Apple ssd ap0128J Media" instead of Macintosh HD and broken software I was preparing my laptop for a sell and booted into recovery mode. I then went into disk utility, selected my Macintosh HD and erased it. When I rebooted I got stuck on a screen with a "prohibited" sign and couldn't do anything.

I restarted my mac holding down cmd + r and got to a screen with spinning globe where I had to select my network. It then proceeded into recovery mode after a while where I now have

Apple ssd ap0128J Media and osx disks as opposed to common Macintosh HD.
I clicked on apple ssd disc and proceeded to erase it. Selected name as Macintosh HD, type as mac os extended journaled and guid partition map.

I now have Apple ssd ap0128J Media and underneath it (nested) Macintosh HD.

I'm not sure about where I should go from here to re-install osx correctly? Any advice would be appreciated.
When you choose to Reinstall macOS you should be offered a list of disks for the installation to take place on. This is where you should see "Macintosh HD" which you're seeing in Disk Utility (as a partition). Do you see this option?