Really not a hard achievement if you're experienced with shooters. This is really just the guidelines and some tips:
Before We Start:- You can get this on Heroic, Legendary, or LASO difficulty. Heroic is the easiest of that list.
- You only have to play the main missions. Side quests are completely unnecessary but may help you gain Valor, which helps with "Who is Max Valor" and also unlocks new weapons and vehicles.
- Boss fights, especially Bassus may be tough for you. I recommend you get better weapons from FOBs before each level
- Take things slow, play carefully and know when to run and hide if you're not up to the challenge.
General Tips- Mobility is your friend. Sprint and use your Grapple hook often.
- Never stand still. Sniper jackals aren't as bad here, but the Stalker rifle and the Skewer will knock you out fast.
- Be aware of potential cover. Look at an area before you rush in, notice pillars, walls etc that you can hide behind.
- Press to scan for objectives and weapons.
If you follow these tips, you can easily get this achievement in a matter of hours. It's no shame if you die 20 times on a boss fight and have to watch a strategy guide. Make use of them if you need them. Happy hunting!