anyone know how to reinstall the software manager (I'm on ubuntu and cinnamon). I think I mistakenly uninstalled it.
What do you mean by 'software manager'? There are several apps which let you install. There is apt (advanced packaging tool. Without a GUI). There is a packet manager, for instance synaptic. There is 'software & updates' on Ubuntu (located in the software-properties-gtk package). There is 'gnome-software'. Mint's software manager's name is mintinstall AFAIK. Both use synaptic to manage installation packets. There you can search for 'software manager' or 'software' and install what's missing....
What you need toknow is Software Manager is a simple GUI. While you have "apt" all is fine you can reinstall all what you want and update and even upgrade the system.