After the cut scene with Captain Anderson and Ambassador Udina exit the room using the door. Turn to the left and exit using door on the left. Head down the stairs and to the left. Go past Avina. Against the rail is what looks like a car. Use Rapid Transit to go to Citadel Tower. Shepard can talk to Avina and the receptionist for some experience.
Once in the tower, follow the hallway and Shepard will see Executor Pallin and Garrus arguing. After talking to Garrus continue around the fountain and up the stairs. Climb the stairs in the background and Captain Anderson will be at the top of the stairs.
After the cut scene and conversation with the Citadel Council head back to the elevator. Head right and then left and follow the walkway to the bank. Talk to Barla Von.
After talking to Barla head next door to the Emporium and buy the license from Merchant. Licenses give additional items to buy from the Alliance Requisition Officer.
Head left to the Rapid Transit. Go to Chora's Den in the Wards. Go through the opening and a fight will begin with some assassins. After the battle, enter Chora's Den. Harkin will be on the other side of the room near the entrance to Fist's Office. Talk to him.
Exit the Den and head towards the Rapid Transit. Use the door control to enter the lower market. Talk to Morlan. Buy the license he sells.
Behind Shepard and to the right will be stairs to the upper wards. Talk to Expat and buy the license he has.
Use the Rapid Transit and travel to Medical Clinic. Inside the clinic some thugs are talking to the doctor. Garrus will kill one. Battle will then begin. Kill the 3 thugs and then talk to Garrus. After Garrus joins, talk to Dr. Michel. She has some armor upgrades that she sells.
Go outside and head to the right and head down the stairs you can see. At the bottom take the door to the left. Go to the end and use the elevator. Exit the elevator to the left and Shepard will find Wrex. After the cut scene talk to Wrex.
Wrex will join Shepard. Go past the Elevator to the Docking Bay and down the hall to the Requisition Officer. Then, buy the license he has.
Now for Fist. Head back to the Docking Bay elevator and there is a Rapid Transit. Use it. Travel to Chora's Den.
Prepare for a fight when you enter Chora's Den.
Kill all in this room. Head towards Fist's office and enter the door. Shepard will run into warehouse workers pretending to be guards.
Tell them to find new work for some paragon points. Enter the door on the other side of room and have a little fight and then a chat with Fist.
After the chat Shepard needs to get to the alley fast. There are more enemies in the bar on the way out too.
Kill them all. Then head back to the Rapid Transit. Don't use it, instead head up the stairs and go through door.
Cut scene will show the quarian and the assassins meet. Then Shepard joins the battle.
Take them out. Afterwards the quarian will talk to Shepard. The party will go to the Ambassador's office. After the conversation Tali joins the party. Use the Rapid Transit and head to Citadel Tower. During the council meeting Shepard becomes a Spectre.
Let's head to C-Sec Academy and see the Requistions Officer. Then head back to the elevator and take it up to the Docking bay and talk to Ambassador Udina.
Shepard gets a choice of where to start the search. Once aboard the Normandy Joker tells Shepard that the intercom is on if he'd like to say a few words to the crew.
There are a few crew and party members Shepard can talk to for background, experience, paragon points. When Shepard is done use the Galaxy Map to select Shepard's destination.