On first run (Normal mode) it is assumed you’ll largely follow main story, so the levels for missions are set (within a certain range).
Triton flats is a bit of an oddity, in that some groups of enemies always scale with the player. These include the Darksiders (in the place with the prism on the roof), the Moonrakers (?) (up where you can find the Oz kit echo and the chests of Oz kits) and others. There are on or two located in order corners that don’t level up, but the ones that do are really helpful if you find yourself underlevelled, as you can run around getting XP and at-level loot from them.
You will be horribly over-levelled for most side quests at this point. The story jumps in difficulty after you take down the laser, and particularly when you got to Varrago Solitude and face RK-5 before heading to the final boss. You’re probably best off pressing ahead with the main story. Note that Concordia lockers etc. will level up at periodic points in the story, but the vending machines will always be at your level. I found I was typically level 28 by the time I’d complete main story.