I'm sorry but this is not Call of Duty. There are no killstreaks. However, the UAV is a vehicle which can be flown on quite a few maps, as signified by a little Square box on the mini-map. As for the airstrike, you may see some planes attacking the ground on some maps, but this is just purely for effect. You can call in a mortar strike, but the tool has to be unlocked for the Recon class, by earning a certain amount of points.
For the attachments, you need to get a certain amount of points with each of the classes to unlock them. So say you want a Red Dot Sight on your Assault weapon, you would need 14,000 score with the assault class. This goes for the other 3 classes however, the score varies for different classes.
Hope i helped