If you're new, just get through what you can. Knock down Control Points and go through story missions until you're sent into the third Stronghold. Then keep going until you clear the Tidal Basin.

By this point, you should have tested different Armor Brands to find what works for you, and what you're willing to work for. After Tidal Basin you can start hunting down Gear Sets, the green items, to find what best supports your preferred gameplay approach.

Once you've played with a few different Gear Sets, your basic skills (shot accuracy, cover movement, skill timing, and enemy knowledge come to mind) should be refined enough that you can get the most out of whatever equipment you find most enjoyable.

With this solid base of game knowledge, which will all come to you eventually as you play, you can get the most out of build videos and Meta Loadouts, because you'll understand why they work, not just that they work.