project build with focus on bluetooth

[0_Write0]

Greetings,
I am learning C++ and for my lab work I have a ESP32. The course has 4 more lab meets. I am totally new to C++, ESP32 mc board, and most of all IOT is a mystery to me. All in all I seek help to be fluent in C++, handy with ESP32 and able to employ bluetooth iot ideally by the end of this week if not within a shorter time. Let me declare that the instructor I have is a wiz, but he/she knows my vulnerabilities so they prefer I research and develop urinarily as much as possible. Forums were at the top of the searchable resources.
My situation: my smart phone is neither ios or android. It can host a wifi hotspot, and has bluetooth. Will that be enough to carry out a simple sensor sketch? Say i want to control led or maybe potentiometer. The gist is not to try building a washing machine, just a small back and forth gear action. Or at this futuristic date do I need the assistance of a cloud based utility? Could I do with a cheap bargain phone that has android?
Next is my experience with bluetooth. Believe it or not like some people have never owned an iphone or android phone I have never needed bluetooth. I know I'm not alone and thats why I'm posting. I know what bluetooth is. I need to understand how the statements and which statements in a sketch control and communicate data from say a GPIO pin for output to the phone? I see alot of pre prepared object programing styled utilities which use android & ios which I'm trying to avoid.
An example I barely understand is Serial() which if I read right is used with the serial monitor. My understanding is serial monitor displays output of GPIO pins. I can understand how to use the ESP in a circuit loop to do a function. Where does my confusion/ lack of understanding lie? I want to learn and be accurate in adding any device function to both the serial monitor and with remote control capability.
How close is the data output to serial monitor and data to send from GPIO to phone or from phone to GPIO. I see the logic statements used in wifi sketches. Where can I find similar controls for bluetooth(library?)? Does the ESP32 just automatically send data to the wifi or bluetooth channels? Knowing what I'm doing would increase my rate of success to build some simple basic device that demonstrates an understanding of language, electronics, and communication.
Thanks in advance.

[chegewara]

I think it may be good start for you https://leanpub.com/kolban-ESP32