| Thanks IronFist, but just in case he doesn't want to make the jump over to AE, let's give him a little kick-start, here.
The very first thing you must understand about building muscle and changing your body composition is that it's 75 percent diet. Food. Lotsa food, and the right food. The workouts are maybe 15 percent of the process, and rest and recovery are the remainder.
So, more than anything else, you are gonna have to be prepared to alter your diet, significantly. Otherwise, you will do nothing but go round in circles.
You will need to eat 5-6 moderately sized meals every day. You will need to drink up to a gallon of water per day to keep your kidneys healthy. You will need to be eating lean chicken, turkey, fish, egg whites, and beef, for proteins, and carbs will consist of oatmeal, brown rice, sweet potato, whole wheat pasta, and lentils. Healthy fats for your diet include extra virgin olive oil, fish oil, natural nut butters(peanut, almond, cashew), avocados, and flax seed oil.
You will have a learning curve, to discover how the 3 macros(protein, carbs, and fats) all fit together in a ratio which is both healthy and promotes muscle growth. You want to build muscle, not fat.
And, very importantly, you MUST eat a proper breakfast, every single day.
Good luck. If you do your homework, you and your girlfriend will eventually have something better to look at, with your shirt off. | 
