I've been playing EQ since launch basically, and I've yet to use campfires lol, not even sure how.
Campfires are far easier than they used to be, first you make your "Fellowship" (shift control F then click create) this will start your fellowship with your character listed. Just a side note: Fellowships have exp sharing that I am not going to get into

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Now target your alts, friends or whoever you want in your Fellowship and click "invite" on that window. You can have up to 12 characters in it. But only 3 of them are needed to be in a zone to make a campfire. If you drop a member or they leave the fellowship then they have a lock out of 20 hours before they can be invited or join again.
Now go to POK and use your find key to locate Randall of the Fellows who is listed as Fellowship Registrar in the list. He will give you a run down similar to what I just did

Next to him is an NPC vendor named Fellow Byllie.
The first thing you need to buy from him "Fellowship Registration Insignia". Well, not buy cause its free but each of your characters will need one and this is what will port each one to the campfire. Its not a group port. You can port every 15 minutes to the campfire.
If you wish to have an "empowered" campfire which will add stats to your group then you will also need to buy "1 Fellowship Campfire Materials" every time you replace your campfire to empower it. They cost 1k plat.
You do not need to buy this if you just want to use the campfires as a port and don't care about the extra stats.
Using the campfire:
Take 3 of your characters/friends to the zone you want and Using the Fellowship window again you will click on the tab at the top that says "camp". Click refresh. You have to click refresh every time you do anything in this window. The default campfire that is just to port to is called "Fellowship of Honor" and is the first one highlighted. So you click that, and then click "create" at the bottom. It drops a campfire and now whoever is in your fellowship can port to that fire using their Insignia. The 3 do not need to stay there - they are just needed to place it.
Empowered campfires are also listed in that window but you have to click the "show all possible" There are just stat raising and illusion/stat options. You have to buy those materials mentioned earlier
Hope this helps, campfires are really helpful in the game