Particle Playground can help create smoke within After Effects.
Add Particle Playground to a solid layer by accessing Effects > Simulation > Particle Playground in the “Effects Panels”. First, adjust the Cannon property by rotating down or up as desired in the “Effects Panels”, while playing your timeline will display its default effect. Afterward, modify emitter width/barrel radius/particles per second/other options that affect direction, spread speed color size etc to achieve your desired result.
As smoke tends to drift upward, reduce Gravity by setting Force equal to zero and using Gaussian Blur on particles to give them more of an appearance of smoke. When playing back timelines with straight up smoke lines, add a wiggle expression for direction value in cannon so that it billows with the wind instead.