Havent tried connecting to it with monitor keyboard and mouse

Let us know what happens when you try.

Not sure what putty is

Putty is just a ssh tool for connecting.

It turns out StartOS has ssh via password disabled. (https://docs.start9.com/0.3.5.x/user-manual/ssh#connecting-via-putty-on-windows)

You would of needed to already download your ssh key to use this option.