This will be your first full blown skirmish in the game. The game will walk you through the basics of setup. Enemy troops won't come until you've setup an instance of each unit you'll be using, so don't sweat it if you mess up on the fan geyser solo (it can be tricky at first). Just keep trying till you get it.
For you people more used to the adventure side of Tim Schafer games, this guide is written to include you in mind.
Tips here after you regain full control:
Get that other fan geyser setup with a merch booth fast!
1. Do not forget to summon squads yourself! The army the game gave you isn't the only units you have. You will also lose units like in any RTS so replenishing them is a must. A squad unit can be summoned if its icon is white.
Speaking of icons, besides the ones in the summoning menu, you will also see icons appear on screen like in the mine mission, telling you point of interest.
Only worry about the red icons.
White just means they're being summoned. Red means they're in trouble. Assist where you can with merch booths taking priority.
2. Summon many Razor Girls for their range attacks. Headbangers are good for brute force but will be hampered by foot speed. And always keep one Thunderhog around for its healing powers.
My suggestion to your own actions is to scatter and stun as many infantry as you can, axing the hamfisted brutes when they come in. Best to stay on foot and use the ground shock move as the Thunderhog's Stun takes a while to recharge.
If you're good with solos you can try using some solo moves but ultimately I found them too time-consuming and dangerous at this early level (time does not pause when you solo and enemies can still attack you).
You can also use the Headbangers' mosh pit combo for additional cover if you want but don't depend on them as you can't use your axe while you're in it. Learn to switch in and out and you should do fine.
3. Don't worry too much about death. Fans will revive you if you die (though it will take 50 fan points).
4. Keep the fan geysers running. They're your source of power! If one geyser's merch booth falls, clear the area of enemies and wait till the geyser's color turns back to green. Then do the fan geyser solo to get back in business.
Keep these tips in mind and follow the in-game directions ("unfriendlies at 11 o'clock!") and you should be fine.
There will be about 6 waves before the fight is over. (I played on Brutal so it may be less for easier difficulties.)
Watch the cutscene (I can't believe that hair!) and enjoy your victory!