There’s two different “discernment of spirits”.The first is the Ignatian method of the discernment of spirits. Anyone can use this methodology. As you mentioned, @Ordinary, this is acquired knowledge.
The second discernment of spirits is what is mentioned in 1 Corinthians 12, which is more commonly referred to as “the spiritual gift of the discernment of spirits” or “the charism of discernment of spirits”. This is not learned, and as Saint Paul mentions it’s given to certain individuals by the Lord to assist in the building up of the Church.
Please note that all charisms require testing and confirmation from others. That said, they do not require “official” confirmation from the Church. I mean, you don’t need the Church to officially say “you have the charism of music” or “the charism of knowledge”.
The charism of discernment of spirits is rare. As a result, the charism is often misunderstood, or worse - people ignore the warnings that one gives when utilizing the charism. I will be honest with you; in my travels I have yet to meet another person who has this charism (I have met people online who have said they have it, though).
Out of all the charisms, discernment of spirits is arguably the main one where you definitely want to pray unceasingly for the Lord’s guidance. It’s also arguably the main one where you want to learn more about what it does, what it means, and how to use the gift to build up the Church. You’re literally able to detect spiritual warfare and/or the presence of evil, which can become incredibly overwhelming - especially because it can be manifesting in physical, mental, or emotional ways. There’s some courses that you can take to help gain knowledge of the charisms; “Called & Gifted” by the Catherine of Siena Institute is one such place. If you know of a spiritual director who is well versed in charisms, that would be of help. And of course, if you meet someone who has had the charism for a long time, ask them about it (which very well could be why you are posting here in the first place).
Anyway, all of this to say; yes, I have the charism of discernment of spirits. It has been tested and confirmed by others.
*Disclaimer; there’s a few traditional Catholics I have talked to who do not believe that the charisms are present today. Some believe that the gifts were only during the period of the Apostles, some think it went away after the patristic period. Others think that you must be like a Saint to have these gifts.
So, be forewarned by posting this question in this section of the Forum, there will be some who subscribe to the thoughts above, and will engage with you in either a debate or dialogue regarding the topic.