First, you need to know your abilities in the initial stages. Try push-ups. They will help you to what you have in terms of physical development prior to the course. Pay attention to the number of repetitions, approaches and the weight that you use.
Do various exercises by using dumbbell. They are relatively inexpensive, so two 10 kg dumbbells with interchangeable weights can help you develop muscles.
Make sure your diet consists of carbohydrates, fats and proteins. After a routine workout, muscle tissue needs to be updated which requires proteins. The most basic and effective natural product for physical condition, is the meat (mainly beef) and eggs. Potatoes and fish can also work. Of course, fruits re important for the general balance and health of the body.