*For the duration of the beginning part, you are going to need to try and not waste time*

Join random games and find a game that is about to end or a game that just started. (The reason for this is that way you are going to start fresh with the rest or join not too late that you're at a severe disadvantage)

As soon as the game starts, you're going to want to grab the scout and build a power plant at the crystal but place it between the crystal and the command center, that way when you're going to place other plants, no one picks it off. Next, you want to grab yourself a good ally before they are taken. After that, with the remaining 235 cash, you are going to build plants on the side that is farthest from normal attacks. Example: If you are near water, place it as far from water as possible so that battleships can't reach, place it as far from the floor below you, that way enemies have to climb to kill your plant in the future etc.

After you finish your starting money, start saving up for more plants until you get around 100 per minute. After that, you will wait two minutes and build a barracks and 3 houses. Sell your units, keep the tank and rack up 13 heavy soldiers. Then find the closest enemy to you and take them out. Send two waves of 13 heavy soldiers if you need to, get the job done and build a pp at their base. If you get set up and prepared for the attack fast enough, the enemy won't have enough money to fight back and their army will most likely be somewhere building power plants. After you eliminate their base, you can let them run to their ally, or they can rage quit.

Look around, and if someone else isn't prepared, train another 13 soldiers and take out their base. If the attack doesn't work, at least their CC is low on health.