that's my first post here. I bought this game once it was released on Steam few months ago, but lately I decided to spend some time in learning it.
Though I playd the tutorial scenario, read through the manual once, and watched Charles tutorial on YouTube; but I'm still quite confused on how this game works

I have only the base game and picked the shortest scenario (in terms of turns) available, and it's the 4 emperors years, or something like that.
I selected Otho as faction just because it owns Rome, is it strategy right?

By the way looking the forces available I thought I'd need one or two legios more, but I can't recruit them, they are just not available in the list of possible units to be recruited.
So now I'm confused, why they're not available at all? I can't find any information about requirements to recruit them anywhere, could anyone enlight me please?
Further, being a noob, what scenario and faction you suggest to start with? (consider I have only the base game)
If there's some pious soul out there that would like to add me on Steam (Avionauta also there), or whatever other means you like, so we can chat faster about tons of questions I might have and why not try a multiplayer session just to be used as let's learn match, it will be an easy win for you guys XD
Thanks!