Find the store entrance is a mission in Going Commando taking place in the Megacorp Outlet area on planet Oozla. After Ratchet left the Unknown Thief's flying lab on Aranos, Abercrombie Fizzwidget played him footage of the Thief robbing a quadrant map from the Megacorp Outlet on Oozla, and deactivating perimeter defenses. Ratchet then went to the store to search for signs of the Thief, and for any life left over.
"Find the store entrance" is one of two you can complete on Oozla, along with "Explore the swamp ruins". It is recommended to complete "Explore the swamp ruins" first for bolts, but ensure that you complete it before leaving the planet either way. Two weapons become on sale in the Megacorp vendor: the Chopper and the Blitz Gun. The Blitz Gun is unaffordable at this stage, while the Chopper fires ranged discs that will bounce around an area. While it is unnecessary on this planet, consider purchasing it in the event that the Lancer upgrades to the Heavy Lancer during this mission; once fully upgraded, a weapon no longer earns experience, and so it is better to instead use another weapon and upgrade that.
From where the ship lands, take the path on the left, with the Megacorp vendor, and a hill leading down. Defeat the mutant swamp beasts and mutant fireflies with the Lancer, then continue down the linear path back to the swamp. Cross the glass platform to another island, and head left to find several mutant muckdwellers attacking a Megacorp employee. Simply kill them with a Gravity Bomb (you cannot save the employee) then carry on, crossing the lily pads to the next island (but don't stand on them too long, as they will sink if you do). Kill all the enemies and continue down the path back to the swamp. Cross the three platforms to reach the next island.
The next island is marked by a large gate. Jump on top of the plateau and head down the linear path, then jump across the lily pads to the next area. This commences the first boss.
Swamp monster I
Only the two tentacles and a single stalk eye are visible, as the monster remains mostly under the swamp water. The monster will attack by slamming its tentacles on the floor where Ratchet stands, but it will telegraph its attacks by first swinging the tentacle around in a circular direction, before then slamming it to the ground. Therefore, the swamp monster is best dodged by strafing left and right, while Ratchet is locked in on it, jumping if needed to dodge the tentacle slam.
The best weapon against it is the Lancer, though the Chopper is also useful. The Gravity Bomb is rather slow and lacks a solid ammunition capacity, but does deal good damage on hit, additional ammo crates are spread out along the edges of the platform if any is needed. Simply strafe and fire the preferred weapon at either a tentacle or its eye to slowly whittle away at its health. Note that the boss gives out a sizable amount of experience points on defeat, thus it is recommended to kill it with a weapon that is not yet close to being upgraded, likely being either the Gravity Bomb or Chopper.