Everyone hits you because your movement is noob and you miss all the shots because your aim is noob. As for ADS, there are talents Reflexes and Combat Training (don't use this one) that are unlocked in the talent tree. Reflexes will help you enter ADS faster and can be very useful especially for sniping long range shots. Combat Training is a weaker version of Stalker from COD MW3/Ghosts. Combat Training would only help for some theoretical range where moving side to side while shooting makes you a harder target to hit, but in reality I can't even see it being useful for the most skilled players. If the hitboxes were tight it might be a different story, but your abilities and general positioning prior to the fight matter more than actual strafing in fights. You also unlock Reflexes sooner so I'd just run that. It's in the right-most tier that defaults to "Leg day" in the talent tree across all classes. It's not an early unlock so just work on the first part of not being a noob in the meantime.