Is Pepe Unchained a worthwhile investment, or should I be cautious?
Sorry, I don't know this Pepe Unchained, but:
If the one introducing you to this would have really been a friend, then he would have been telling you more on this topic.
Since he didn't, then it's either not a friend, either it's just you advertising that altcoin or token (sorry, I don't know what it is).
So, shortly: beware of FOMO advertising, do your homework properly and invest with caution.
I will add that all altcoins I've invested into have disappointed me - sooner or later. You may want to consider taking a look on bitcoin before going for the much more volatile altcoins.