Running ZG is going to be pretty tough, unless you have some people ready to go and who have run a lot of instances with you. Not to say it can’t be done.
That said probably the first thing to do would be to start running a lot of dungeons, start building up a friends list. If you have a guild which has people who want to do stuff that will be a good help also, if you don’t you should probably put that as a top priority. If you have a guild, talk to your guild leader about wanting to step up and be a raid leader.
Run ZG with every group you can get into, take notes as you go through, prior to doing this, you should have a good understanding of the fights as well as the overall raid, such as the pulls, the routes, and general mechanics on both the bosses as well as all the trash. If you don’t know the raid, nobody is going to want to follow you at this stage, some of us have done the instance 50+ times and the back seat driving will start coming out. That will get frustrating for you real quick.
Once you have a good idea of the instance, talk to the people you know, see if they would be interested in running a ZG, assume if you can get 10, your might be able to get an additional 10 in LFG and with a post on your discord server, the more you can have at the start, especially healers and tanks the better though. Nothing kills a raid like having everyone ready to go but not having a main tank.
That said, you need to be able to call the shots, manage loot, and explain all the fights to people on the off chance they haven’t gone before. Being a raid leader even for an instance like ZG isn’t easy. If you haven’t run a raid before, maybe start working on dungeons and work yourself upto UBRS, and get prepped for doing things like Kara in the future.
Additional key things, making sure buffs are managed, managing loot, though for it I would probably recommend a basic MS/OS system, that’s the simplest and likely to cause you the least amount of problems. Setup your own discord server if you don’t have a guild one you can use.