It's best if you don't worry about this too much until the end of the game. Getting the Drone Teleport and Red Lab Coat allow you access to the entire map, as well as making some difficult sections far easier to get through. You will get this on your way to collecting all of the items in the game and attaining the 100% Items trophy.
The 100% Items trophy in Axiom Verge worth 227 pointsAcquire 100% of all weapons, tools, upgrades, and notes. There are 27 Notes to collect throughout the game, but they don't provide much in the way of useful information except for a couple of passwords for your Password Tool. Several of these are labelled just "Journal Page" unfortunately, so it can be a little hard to keep track of what you've collected.
Remember to use the passwords "REVEAL-SUDRAN" and "REVEAL-VYKHYA" to be able to read the notes and their titles.
Journal Page (Purple)
Reply: The Outsider (Green)
Sudran Translation (Purple)
Journal Page (Purple)
Public Notice (White)
Journal Page (Purple)
My Lovely (Green)
The Outsider (Green)
The Breach (Purple)
Athetos (Green)
Axiom 1 (Purple)
Vykhya Translation (Purple)
The Kuliltu (White)
Oracca (Green)
From the High Priestess (White)
The Land of Civilized Kings (White)
Anonymous Quote (White)
Official Letter (White)
Faded Note (Special Brown Scroll)
Transcription (Purple)
Plan B (Green)
The Storm (Green)
Drones (Green)
English (Green)
Security Notice (White)
Proverb (White)
Trace (Purple)