Here are some of the most common myths when it comes to OpSec
While the US government is one of the entities that helps fund the Tor Project, they don't do that to make Tor insecure. The US government has used Tor themselves in the past, it is not only helpful to civilians, but it is a valuable tool for government agents when they need anonymity. For instance, when they are in a hostile country and need to contact home. Tor relays are also not ran by the Tor Project, they are run by completely separate entities such as individuals who voluntarily set up relays on their home internet and non-profit organizations.
This myth is usually spread by VPN companies trying to convince you to use a VPN with Tor. Tor is encrypted, in fact it uses 3 layers of encryption. When you connect to an onion site, the encryption is even more effective because the traffic stays encrypted using Tor all the way to its destination. However, most sites use HTTPS anyway, so this isn't even an issue. The point is, Tor is encrypted using strong and reliable algorithms that are properly implemented.
There is no way to be 100% anonymous, you can get close to 100%, but you will never get to 100% anonymity, it simply is not possible.
No it isn't, don't use Telegram. Telegram is not private, they do have secret chats that use encryption, but these are not turned on by default and most don't even know they exist. On top of this, Telegram rolled their own crypto, their secret chat encryption is questionable. While it is public how it works, it really isn't very good. If you want a messenger for privacy, use Signal, if you want one for privacy and anonymity use XMPP with OMEMO over Tor.
ProtonMail is not private or anonymous. They have been seen on numerous occasions giving law enforcement identifying information about specific customers. You shouldn't rely on a company or a product to keep you anonymous. ProtonMail also doesn't encrypt any metadata such as the subject lines of emails, even though it is widely supported by many email clients that support PGP.