Execute random php file with bash script

I'm newbies with bash scripts, so please, be indulgent ;-) !!!

I would like to read php files randomly in a pre-defined folder (there are 30 php files in this folder).

My current script:

#!/bin/sh
curl "/myfolder/myfile.php" &
exit 0

With my research i've already done, i've found some examples but i'm not sure of anything with my little skills.

I know i must use an "for ls" and then do something like "echo $ ((1 + RANDOM% 30))", but i'm not sure !

Could you help me please?