Simply setting up a discord server allowing people with a similar interest to meet won't get you into trouble if two them meet up in person later and something bad happens as a result. But of course the details of your involvement in the matter and what you knew of the people participating on the server would be important.
If your Discord server is used for nefarious purposes in violation of Discord's terms of service, your server can be disabled and you can be banned from future uses.
Depending on the reasons behind the "meet ups" and your involvement with them, you potentially could find yourself in legal trouble. The Communications Decency Act's section 230 can provide you with some immunity but only stretches so far. You potentially could be sued and/or arrested, in other words.
Consult with an attorney in your area for direction.