First, rename "Campagin" to "Tutorial/Campaign" so new players will know where to start without checking the manual to know that campaign is actually a tutorial. New players shouldn't be forced to read the manual so to know how to start to learn playing.

Second, make that damned thing fun! First mission should show new players the fun parts of the game, like combat, magic, developed cities, powerful artifacts, conquest etc. I spent 10 minutes reading walls of text and looking at my 0/0 stats naked hero, and zero-level city, and i decided that maybe i'll play Elemental tomorrow. Come on, you're developing games for like 15 years, and you don't know that the first 15-30 minutes of the game should be one of the most fun moments so to hook the players? Even i, a long-time player and an amateur game designer, know about it.

So, make a menu with a tutorial/campaign missions or something, like in other games. First mission should be the overview of the game, should hook the players and should be short and fun. One or several next missions should be a tutorial missions (that you may skip if you want). And the first mission of the real campaign (if any) should be unlocked at the start as well.

Also, make a tutorial missions with a certain theme that should be mentioned in the name of the mission. Say, if i want to look how combat looks and is being played in Elemental, i should be able to pick a "combat tutorial" first etc.