This trick will enable you to project your friend's device(android 9+) live time and in some android devices you can even control it remotely if you share same wi-fi.
Requirements

• A computer/laptop
• A usb cable
• Internet
• Your friend's phone for 20-30 seconds unlocked.(just like in the movies)

Steps

1. Get Your friend's phone enable developers Options in his phone. These are hidden settings that are usually enabled by tapping build number in About-phone settings.
2. Enable Usb Debugging and Usb Debugging-Security-settings(for controlling) in his phone. As shown in the picture. It is suggested to not change any other setting in the developers options.
3. Now there is a very nice project on github named SCRCPY. This blog is just a noob use of that project for fun.You can download it from this link.
4.(Only for windows users)After download extract the zip and open the folder in CMD in which the executable are that is scrcpy.exe.
5. Plug you friend's phone and the phone will prompt about the rsa signature of your computer. Accept it.

6.Now In the
cmd (withing the same folder with scrcpy.exe) type

./scrcpy 

for Linux Shell just type

scrcpy

This should start projecting your friend's phone screen on your computer. Now connect both the devices with your hostel network(this is required for wireless connection)

7. now in the same terminal press ctrl+c and enter
windows (withing the same folder with scrcpy.exe)

./scrcpy --tcpip

linux

scrcpy --tcpip

for linux this should restart the projection but this time you can unplug your friend's phone from your computer.
8. Now you can connect to your friend's phone anytime from your terminal by just entering
windows (withing the same folder with scrcpy.exe)

./scrcpy

linux

scrcpy

And can control it using your mouse and keyboard if you had enabled Usb Debugging-Security-settings in his phone.For additional controls like power-button and volume up/down follow their documentation.
If you find scrcpy helpful for you then star it on GitHub as well.