The following link may contain spoilers, so don't click it if you don't want it!

https://valheim.fandom.com/wiki/Events

TLDR;
"Events have a 20% chance of starting every 46 minutes if there is a player within 40 meters of at least 3 base structures (except for the "You are being hunted..." event which doesn't require player base). The event is randomly selected from available events."

Have your friends give you their gear they've leveled past and keep food buffs up. It's being near the workstations that are doing it.

Following is a list of all crafting stations/'items' that count as Base Structures.
https://valheim.fandom.com/wiki/Player_base