and what exactly is a render?

isnt it the same as a regular photo?

its a cut out from a picture

You should start off from making a background (bg), the render is your main theme/picture on your signature ( like the wizard on yours and grim reaper on mine ).

There are lots of ways.

You don't need render to start making signature, some pictures have no renders. Just some pictures and stuff, but you can start making signature just from a render. And only from render. There are like, Millions of possibilties to start siganture

In the context of this forum a "render" is just an image that has a transparent background.
In the proper context, that is, 3D modelling, a render is just basically a screenshot of whatever your screen is looking at, except effects like lighting and shadows etc are put in, they're not normally shown in the software to minimise load times.