Welcome to our guild Devo076. We have fairly active groups in both the Horde and Alliance factions in wow. But when deciding your faction, your choice can be both. Many of our members have characters on both sides of the faction divide these days. Alliance is located on Anvilmar and Undermine servers, while Horde is on Kul Tiras and Bladefist servers.
Because they are housed on different servers entirely, you still would be able to chat in Discord with everyone even though your toon would be on one server or the other, depending upon the faction you play on. I have a Horde hunter and a few lower level toons on our Horde servers and switched to the Alliance side at the beginning of BfA because I’d never played through that story line and wanted a different point of veiw.
Currently my main character is a Warlock which I use to run with our Alliance “Misfits of Mayhem” raid group twice a week. But since I initiated my wow play back in '07 on the Horde side, I decided to try out the Alliance side at the start of the current xpac BfA. You will find each group to be interesting and very helpful in similar ways. But we are all one big family. As I said earlier, many of us play both Horde and Alliance factions anyway.
Try both sides out and see which story line intrigues you…or just create toons on both and swap between them to change your flavor each day as you play through each story.
Only caution I can provide is make sure you create your toons on the server(s) OTG has their guild in game setup. I created a toon a year ago to play on but when I actually tried to get into the guild I realized I was on the wrong server and had to either pay for a server swap or just delete that toon and start over on the server OTG was on. A little egg on my face when I realized I had done something so silly.