You start with three angry mobs and an underdeveloped base. You can use the mobs to destroy buildings very easily to gain cash to build up your base a bit. It's wise to do so because if you lose the mobs, your base would be undended. I recommend you destroy the building just north of your base and take the crate to grab a nice $1500. You can take the cash bounty (2 levels) general's upgrade to help you should you destroy any enemy units. You can also take repair to help the vehicles that should be guarding your base. Build an arms dealer and pump out about 3 quad cannons and 3 scorpion tanks.

Take your angry mobs and group them together, destroying buildings. When you reach this bridge to the northwest, leave one of your mobs there to guard to keep the americans from coming to attack. Use the other two to continue your destruction campaign. This is a very easy mission and it shouldn't take you too long to get the $40,000 if you stay on the move. Three angry mobs is just a very tough thing to take down. That's why the Chinese and americans have easy ways to do so (dragon tanks and flashbang grenades). Even the GLA can take down a mob with toxin tanks without too much trouble. If they're left unchecked they can wreak havoc. Now that you're using the GLA this mission is a good learning experience for you.