the schematic can be found on this page https://github.com/m5stack/M5Stack-UserGuide/blob/master/ESP32CAM.md
The empty footprints are bottom left of page 2, the MPU60x0 (gyro ) and SPQ2410HR5H which appears to be a microphone. I might try fitting an electret later and connecting it to pad 4, gain might be an issue though.
I have seen old ads for them listed with the extra parts fitted for 3 times the price of this module, I think now sold out.
The flux is normal and no big deal, if the LED works then it is not shorted by solder blobs, mine did not come with a lens cover either, the price for the entire module with ESP32 is cheaper than what I can buy the camera for, not expecting gold class here :)
oh, the "demo" software as mentioned by jeff above sets it up in access point mode and then you can open either 192.168.4.1/jpg for a single image grab or 192.168.4.1/jpg_stream for a live feed
the firmware is also on the page I linked, the page was branched from a previous demo by igrr and nothing has been edited so it does not properly explain either the hardware setup or the firmware, ie .. there is no ascii image output..