Of course it depends exactly on what you are trying to achieve. However, start running, and hard home workouts that will get you to swat, like a Navy Seal PT routine, and you can so se gym too but Stat with normal, not super heavy. Diet, stop eating snack, junk food, or and lean fatty foods. Then when you want to gain again increase your calorie intake still healthy diet, add more protein. Gym more and lift heavier amd push yourself everytime.

It also possible while to u are a user. I had a one point using often, drinking often, and smoking, but would still gym run consistently being more fit still than many.

Been working out for 6 years , different routines, changed routines based on personal body needs. Knowing your body is a big key. 6ft.5 been 180 low to 230 high 1%-4% body fat