No, you only unlock boosters and skins when you level up.
you level up and earn them all
You have to be online, and the only way to unlock guns is to level up. Just keep leveling up and you will start unlocking guns, perks and new challenges.
The guns themselves can gain experience, and the more you use them, the more they get. When they level up, you unlock attachments, proficiencies, and skins for them.
For each weapon class, as long as you keep getting kills or other points while using that class, you will level up that class and unlock more guns for that class.
u dont unlock guns they give u guns at the begining of a mission then u can pick them up off the ground
They are unlocked as you rank up but you have to buy them.
The stuff? Could you be more specific. If you mean guns on single player then you can buy them, pick them up or unlock them. Guns online you unlock through ranks, however you can pick them up, but do not keep them.
Unlock By Leveling Up, And Purchasing With COD Points
Leveling up to the level where you unlock chickpeas
You must play Multiplayer and level up each time you level up you will be able to unlock things.
you level up to level 80
You use the default classes set by the makers of the game to get to lvl 4 that's when you can unlock guns and XP, you can also gain more XP by completing challenges and getting cool camos for your favourite guns.