ESP32 as a sensor with MicroPython

[pijnxiii]

Hello.
I have to inform you that I am really new with this stuff so I am facing a lot of problems right now.
I have connected my raspberry pi to a display screen(monitor). On my raspberry pi are also connected the keyboard, the mouse and the ESP 32. My connection to the internet is via WiFi.
I am trying to download and flash microPython, but after the : $pip install esptool, all I get is: bash: $: command not found.
For example, when I type : esptool.py --chip esp32 --port /dev/ttyUSB0 erase_flash, the "command not found" appears.
I have searched on the internet to amend my issue, and I saw that if I am using Linux or macOS , ttyUSB should work. But if Im using Windows, I should change this to: COM1.
In my case, I don't know what is the operating system, because I am just using a raspberry pi connected to a monitor .
Could anybody help me?
Thank you in advance.

[ESP_Sprite]

The $ is not part of the thing you need to enter. Entering 'pip install esptool' (without the quotes) should work (given that whatever you have installed on the RPi has pip installed)