Even though there are different instances, we are on the same social network. My favorite analogy is it works like email: a gmail user can send an email to an outlook user; similarly a lemm.ee user can subscribe and post to a lemmy.ml community.
It was confusing for me at first as well, but it's not as complex as it sounds.
It's not forbidden to create a similar community on this instance, and there are plans to somehow link communities on different instances. So if you want to mod you can stay here, just don't expect that this will be THE f1 community, as there are 2 already active ones. I've seen other communities close down for this reason, e.g. there were 2 similar sized formuladanks, and the second one was closed after the mod figured that there is already one.
I recommend getting familiar with how lemmy works before opening communities. A good starting point is the new communities community: [email protected]