As awkward as it may feel, but if you are the only person creating content, then there IS content at least. It doesn’t make sense to do nothing and just hope that other people will eventually fill the void, as random visitors will take one look at the community and think “eh, it’s empty, no use in staying here” and just move on. Someone has to make the first step.
Of course a little bit of advertisement can’t hurt as well, but content comes first.