If you're interested in building the Alliance right away, go to the moon on Palaven after the dream sequence with the child and introducing yourself to the crew, both old and new.
Meet General Corinthus[edit]
You're limited to James and Liara as your main squad. Your AI squad always consists of two guns and powers only unique to them. Anyway, you just need to take down those husks before going into the camp. Don't forget to ask the Turian soldier first. In the camp, before you talk to the general which happens automatically, look around the camp to gather experience, credits, guns and mods. That includes going to the weapon dock on the left side of Corinthus place.
Fields of Husks and Communication[edit]
General Corinthus is running his camp and it's chaotic. He wants you to secure the Communication Tower which needs to be repaired. So go ahead and move to the left end where the metal door opens. Climb the area and move all the way to the other end where the tower is. Take care of husks along the way and ask either Liara or James to fix the tower link. It's pretty much shoot the husks until the other comes to join you and Corinthus calls you back to his camp.
Garrus returns[edit]
Corinthus tells you the previous general has died prior to your arrival and has found another candidate. If you're fresh in this game, it's presumed that Garrus has survived the suicide mission back in Mass Effect 2. Anyway, go back and check his weapons and go back to the field to take care of more husks and marauders. Then go back to the camp and up the ladder to take of the remaining hordes of husks. The brute drops down and knocks you down over to the ground. Get your team to focus on brute and take care of anymore husks.
Trail to Victus[edit]
At this point, you can't get back camp since they have no ladder on the other side. Instead, you have to follow Garrus to his commander. Along the way, there's a few husks, surviving turians and a fighter plane crashed! Make sure to collect along the way because you won't be able to replay this level again. Once you reach Victus' camp, take care of the husks, brutes and marauders before telling General Victus that he's going to be the council to represent his people because the previous council died. This marks the end of the mission after a brief with General Hackett and your next goal is set a meeting with the salarians and the krogans.
The last Prothean[edit]
Unless you have downloaded this content or already own the Wii U version, you may or may not have this mission at all. Just because you seen every race, doesn't the Prothean count too? It's a pretty straightforward mission in Eden Prime. But make sure to go to three computers in different location to add to the war asset. Anyway, follow the path and turn on the elevator. Liara is shocked that there is a live Prothean in a coffin. But it can't be open without turning off the transmission stasis mode. So cross another bridge and follow along the right side in an anti-clockwise motion. Once you reach the door after dealing with Cerberus, your first vision reveals the battle 50,000 years ago.
After the vision, when you go out, deal with more Cerberus and check along inside the chamber until you reach another door that needs to be open. The second vision shows the battle losing control, forcing the Prothean to close it doors and go up north. Go back out and handle more Cerberus forces while going back to the coffin but the bridge is gone! Not to worry, follow the path and move up two ladders. Then follow the path down the ladder back to the coffin.
After you open the pod now the stasis has been neutralized, Cerberus will make a final attack so finish then off, including the mech which is huge in size but can be easily defeated after some bullet pounding. Go back and you'll see the Prothean recover and stuns you down. Liara warns of his confusion and the moment you touch him, the final vision comes. With little choice, the Prothean leader goes into the coffin to remain in stasis until your team came in. After bringing him up to speed, your team goes back on the Normandy. But after a brief with Hackett, your called down to the Storage Center where it becomes the Prothean's space.
Once the conversation is finished, he wants you to call him Javik and he'll be your squad mate. Depending on the order you go through, Javik as a squadmate won't be available until after the Primarch mission. If you want to know a little bit of his character, he's astonishingly honest, even when he touches anyone and can be normally philosophical on his views. Also he can comment the difference between today and his time. Having him in your team will add additional incite to his views as you play through the game.