The area around Colony 9 that it is safe to explore at this point is actually rather complexly laid out, making for a lot of confusion if you don’t check your map regularly and otherwise keep a good grip on your bearings. The core of this area is, of course, Colony 9 itself. To the Southwest of Colony 9 across a bridge is a hillside, which both slopes down to the lakeshore and up to three paths- one clings to the side of the cliff heading East, and leads to stairs that will bring you to Lookout Park. The other two head South before diverging- the Western path simply ends in a cul-de-sac with some Mechon wreckage in it, where the East path climbs the hill and leads to Tephra Hill and Tephra Cave, although it passes over an extension of the lake and an additional segment of lakeshore first.
Of most note is the lake itself, which Colony 9 sits above. This lake is irregularly-shaped, and for the time being, only the parts to the West and the direct North and South of Colony 9 are actually safe for you to traverse.
More Westwards, the lake continues out underneath the land bridge that holds the cave you already passed through heading to Colony 9. There is an extensive lakeshore along the South edge of this arm of the lake, and a few smaller sections of shoreline North of it. This is the area where you can find Lake Flamii, a few Baby Armus, and if you need them, additional Piranhax.
The shore that connects to the bridge to Colony 9 is the area to search for Colony Krabble, Cute Brog, Caterpile, several kinds of Bunnit, Little Vang, and Skeeters.
You will likely find yourself wandering around a lot, as the little blue lights that signify Collection items only appear outside of visual range- and this is a good thing, as it gives you a good prompt to define all of the area around on the map.
Despite being part of Colony 9 and therefore devoid of monsters, Lookout Park does not actually have any people in it normally, so don’t expect anyone to show up there for you to trade with or get a quest from.
You will also want to keep a watch on the big metallic outcroppings that rise from the lake. These strange features not only hold the Anti-Air Cannon that protect Colony 9 from both aerial assault and falling random debris, they also serve as both excellent places to find Collection items, and a landing spot for a particularly dangerous flying monster that you aren’t likely to be ready to face yet.