Ok, as far as I know, there is no command to make cameras unless it's a command for DBPro. Take out the "make camera 1" and also the cls command in your main loop. If you're always clearing the screen, how can anything show up?
So your code should go like this:
autocam on
sync on
sync rate 0
backdrop off
hide mouse
set text font "arial bold" : set text size 20
set text to bold : set text transparent
make object sphere 1, 500
show object 1
do
abc$ = "FPS: " + str$(screen fps())
text 1, 1, abc$
sync
loop
show mouse
Hope I helped.