The mistakes to avoid

[Critical Mass]

TLDR: There are only really two mistakes with long term consequences to avoid in Once Human: losing great calibrations and losing great mods. If it is Gold keep it until you know its worth.

The following advice is primarily aimed at beginner players. Some of the terminology might not make sense yet but

DON"T BREAK DOWN GOLD CALIBRATIONS unless you know they are not worth keeping - break down blue and purple ones whenever you want.
DON"T SELL GOLD CALIBRATIONS unless you know if they are worth keeping - I bought a Legendary pistol Rapid Shot Style 2x Crit Rate (+15.1) calibration for 3000 Energy Links in a vending machine.
ONLY USE GOD ROLL GOLD CALIBRATIONS ON TIER 5, 6 STAR LEGENDARY WEAPONS (or if you really want then tier 5, 5 star Epic weapons) and once you have that weapon never lose it. Maybe even transfer it into your new season with your limited transfer points.

DON"T BREAK DOWN GOLD MODS unless you know they are not worth keeping - break down blue and purple mods whenever you want (but keep your best blue armor mods because they can be used in end game builds on the chest armor if you want to maximize damage).
Mods can be removed from weapons you add them to so use them when you have them. But the luck involved in getting the best combination of 4 extra effects and rolling buffs 5 times on the most important of those is extreme so don't break down your great gold mods.

A third mistake some would say has long term consequences is wasting Starchrom.
This can be from missing opportunities to earn Starchrom, spending Starchrom inefficiently and upgrading blueprints inefficiently.
Ultimately though if you keep playing there will be more starchrom and nothing you can get with starchrom is lost forever by making a mistake.
The menus on Once Human are a confusing mess but there are a lot of ways to earn starchrom in the events menus. The main thing is to get as much as you can each month from the stellar stairway. Just playing regularly should achieve that.
Ultimately if you keep playing, you will get enough Starchrom to get max stars (6) on a full set of legendary armor (6 items) and weapons (3 items). I have played less than 3 full seasons and I have achieved this.
Since the stars are transferable you can be fully decked out with max star gear with only one 6 stack on a legendary weapon and one 6 stack on a legendary armor item but waiting for more blueprint conversions to move the stars around is painful.
Long term you only need Starchrom to unlock new weapons and armor. There is nothing you can permanantly lose by being wasteful with Starchrom but I would recommend starting players buy the blueprint for the weapon they most want and the armor that goes best with it (one key armor, three or four pieces of a set and one or two that give a useful buff - don't buy items for the same body part). Then use the random game in the wish machine, only buying blueprints if you really want to try something new or when that blueprint will give enough Blueprint XP to increase your biggest stack of stars by one.
DON"T USE GOLD GEAR BLUEPRINTS TO UPGRADE STARS ON LOWER RARITY GEAR.
Where possible only use gold blueprint fragments to upgrade the same matching item because the XP is doubled for matching items.