I am very new to arduino and electronics in general. Can i use the NodeMcu Esp8266 as one of those usb wifi dongles? I want to use it as a monitor mode capable wifi card, for my linux laptop.
No, you can't. All you have is a UART interface through a USB to UART adaptor. It can only ever be a UART.
The best you could get would be to write a program to run on the NodeMCU that did the monitoring for you (assuming you can get it into a suitable promiscuous mode) and report information back to you through the UART.