Are there any good topics video or picture learning step by step the verification
If you prefer a video tutorial, I found a helpful resource on how to verify Electrum signatures using GPG software on Windows. You can check out this YouTube video:
Keep you Bitcoin Safe from Phishing and Scams. Verifying Electrum Download Signatures via GPG4Win.
If you have any doubts or need further information about verifying Electrum wallet or any other aspects of using Electrum, it's always a good idea to check the official Electrum documentation. The official Electrum documentation can be found at
https://electrum.readthedocs.io.