RE: How To Access The Deep Web On Android device safely

I have the following comments about your article.

It is not the deep web that is notorious for illegal activities - it is the dark web. You are correct on the part of "the deep web cannot be indexed by search engines" though. The difference between deep web and dark web primarily lies on the dark web requiring use of specific software such as the Tor (The Onion Router) browser or I2P (Invisible Internet Project), while the deep web is accessible using a regular web browser if you are authorized to access such content (normally by providing a username and password combination). Generally, the deep web is not dangerous.
The Orbot software is obsolete. While it is still available on Google Play Store (and other sources such as F-Droid), it has a lot of issues that makes it almost unusable. The Tor project team themselves discourage the use of Orbot, and instead use the TBB (Tor browser bundle). Also, The Onion Router uses the acronym Tor, not TOR.
Some antivirus software spy on your computer without you knowing. Your example is Avast. When you install Avast on your computer, it installs its own SSL certificate on your host machine and/or your web browsers, where it can read all the private data you provide on websites (such as passwords and credit card information). That is just one example of them spying on you. The same goes with many other antivirus software.
VPNs increase your privacy but not guarantee it. Also, nearly all free VPNs are too risky. Most VPNs (especially the free ones, but not excluding the paid ones) will still either log your online activity and/or leak your IP address or DNS requests. (I recommend ProtonVPN whether you intend to use its free features or paid version, but I am not making guarantees.)