The main Priest sat down and a young unidentified man stood up to give the homily.
Can you clarify what you mean by “unidentified”? Was he a deacon, priest, or bishop? Was he dressed in clerical attire? Or was this just some layman?
He said that the ascension was not literal that Christ had always been with God.
I think that qualifies as “heresy”. Sorry.

It’s certainly not Catholic doctrine.
The next week he said that the spirit had always been with the people and they did not literally talk in tongues.
I think that also qualifies as “heresy”. Sorry again.

To deny that the Holy Spirit was at some specific point in time
sent is denying a Catholic doctrine. And to claim that Luke was lying when he wrote that the disciples spoke and the myriad listeners heard
in their own languages is to question the accuracy of Scripture.
Seriously, what else is this guy going to teach?! He could start arguing that, since the Spirit “had always been with the people”, it’s with us all the time, and we needn’t be baptized, we needn’t repent of sin, etc. And that there’s a lot more in the Bible that we don’t need to take literally (like that Jesus is the Way, the Truth, and the Life; or that the Eucharist is truly the Body and Blood of our Lord). He’s not teaching the Catholic faith, that’s for sure.
I’m now bothered too because the Catechism is clear on the Ascension as being Literal. However, I still can’t get my brain around why I’m bothered or why it is so significant spiritually - I’m sure because of my lack of knowledge and protestant upbringing.
Think of the people who
don’t know that the Catechism says the Ascension is literal. Think of the people who will just assume, since they heard it preached at Mass, that it’s the truth. That’s what bothers
me. I might know better, but some people might not, and their faith is being poisoned… at Mass!
Can someone explain the significance and also tell me the route my friend should take to “report” the misguidance.
First, contact the priest (or your pastor) about your concerns. The man was not speaking the Catholic faith, and if he’s not ordained, he’s not even permitted to give a homily at Mass. (I suggest writing a letter first, but maybe you are comfortable speaking directly.)
Second, if nothing happens, send a copy of the letter (if you wrote one) and your explanation of the events to your Bishop.
Third, pray for your priest, pray for that misguided man, and pray for the people at your parish who might now be confused and troubled because of what they heard.