There are a total of 8 Resistance missions in the game. They are found across the following Hubs; D’Qar (3), Takodana (1), Jakku (2) and Starkiller base (2). The missions are given by NPCs who will have a green circle in front of them and a Resistance emblem above their head.
D’Qar
The first mission is given to you by Leia who will be straight ahead of you when you spawn on D’Qar and is a simple cover shooting section on Starkiller Base.
The second is given to you by Admiral Ackbar who can be found by the leaving the spawn building and heading to your left, he will be stood in front of the last building on your right. This mission simply requires you to beat 3 groups of 5 Resistance soldiers in combat.
The third is given by a Resistance general who can be found in the building behind Admiral Ackbar. This mission is a simple shooting gallery requiring you to shoot 10 targets.
Takodana
This mission is given by Pru Sweevant who can be found near the Millennium Falcon (forward and to the right from the spawn position). This is a microfighter mission in which you must destroy 9 TIE Fighter microfighters.
Jakku
The first mission is given by a Resistance Villager (from spawn head to your left, left at the junction and then right when the path splits). In this mission you will have to destroy 15 TIE fighters, followed by a second wave of 10 more.
The second mission is given by a Resistance member who can be found by following the other split path. This mission requires you to retrieve a Resistance ice cream shipment from the First Order. Simply follow the stud path to Niima outpost and defeat 20 stormtroopers.
Starkiller base
The first mission is given by a Resistance pilot. To find him from spawn turn left and follow the path, you will reach a junction turn right here and follow this path. You will reach an open area continue in the direction you were travelling and you will eventually find the pilot trapped in a cage. This mission requires you to free the pilot from the cage. Behind you will be a point that requires a quadnoculars character (Poe for example) use these to turn the cage into silver lego pieces. Switch to a character with explosives (Chewbacca for example) and destroy the cage. This will cause a Wampa to spawn from the cave above, defeat it to complete the mission.
The second mission is given by the same pilot and is located back near spawn simply turn right at spawn rather than left as before. This is another cover shooting mission which requires you to destroy 3 troop transports. Simply shoot the explosive barrels next to them to destroy them. The middle transport will require the use of quadnoculars and explosives as in the previous mission.