what size does the file need to be to post pictures

[Dadshoes]

Hello, my name is Don and I am new to this forum.
I have tried to post pictures of my car, but I keep getting the red letters telling me the file is too large. I assume this means too many pixels?
Any help would be appreciated. But try to keep it in terms a novice can handle please.
Thank you.

 

[Dadshoes]

I figured it out. it turns out there is a setting on the camera to limit the size of the picture.
I am not camera or computer savvy. I just tried every angle until I stumbled on the right one.