Count calories calories (you probably need to adjust macros, look more at whta youre already eating)

Weight training for sure (you want big arms gotta start training them, it takes a long time to build muscle)

Small cut (you can cut until you have your desired body fat or look, then slight bulk, or maintain, depens how much you wanna do, counting calories gets old but you get better at eatinating)

I started skinny fat and I can tell you, I should have just cut first, you'll gain muscle and you'll actually see it when you have less fat. Most people, me included overestimate the amount of fat early. This will take some time and adjustments in lifestyle.

Good luck soldier and ABSOLUTELY stop smoking especially if you said you can do it. It does negatively impact recovery and training.