The Best way to understand how to send and receive Bitcoin transactions without any risk - is to try out and learn with TESTNET
This Guideline is for Electrum wallet (for other wallets will be added on demand).
[0 step] Before setting up an Testnet, it’s essential to run Electrum at least once in Mainnet mode to add essential files that Testnet Electrum will need to run further.
for MacOS
[step 1] Run Terminal. Paste this text to open Nano editor:
nano ~/Desktop/electrum
[step 2] When Nano is opened in Terminal paste this text:
#!/bin/bash
open -n /Applications/Electrum.app --args --testnet
When you’re done, Nano should looks like this
https://imgur.com/a/6tyMfmN [step 3] Save file in Nano: ctrl+x -> Y -> press Enter. And Electrum file will appears on your Desktop.
[step 4] Paste to Terminal text:
chmod +x ~/Desktop/electrum
Now your Electrum icon became executable. Find electrum icon on your desktop and Double-click it, this should start Testnet mode.
for Ubuntu
[step 1] Run Terminal. Paste this text to open Nano editor:
nano ~/Desktop/electrum.desktop
[step 2] When Nano is opened in Terminal paste this text:
[Desktop Entry]
Type=Application
Name=Electrum Testnet
Exec=electrum --testnet
Icon=electrum
[step 3] Save file in Nano editor: ctrl+x -> Y -> press Enter. You should see an file labeled “Electrum Testnet” on your desktop.
[step 4] Paste to Terminal text to make file executable:
chmod +x ~/Desktop/electrum.desktop
Double-click the icon. This should start Electrum in Testnet mode.
for Windows
[step 1] Copy the Electrum launcher and paste the copy on the desktop. Rename the copy to “Electrum Testnet”.
[step 2] Go to “Electrum Testnet” launcher properties:
right click, Properties [step 3] Under the “Target” field append the following text:
--testnet (a leading space is required, and there are two dashes). Click OK.
When you’re done, Properties window should looks like this
https://imgur.com/a/uQTTKFF How to receive your TESTNET Bitcoins
[step 1] Go to Bitcoin TESTNET Sandbox
https://testnet.manu.backend.hamburg/faucet [step 2] Paste your receiving address into the form field labeled “Your TestNet Address” -> Check the box “I’m not a robot” -> click the button labeled “Give me some coins”.
[edited] Don't forget to send Testnet Bitcoins back. Please send left coins to 2N8hwP1WmJrFF5QWABn38y63uYLhnJYJYTF.
* This topic is based on this article
https://bitzuma.com/posts/a-beginners-guide-to-the-electrum-bitcoin-wallet/#funding-your-wallet. I have tried out myself on macOS.