You don't need to go to the gym if you want to build a strong upper-body. In fact, there's a whole world of dumbbell exercises that will help you to develop strength in the muscles in your back and arms.
Plus, you don't need to lift super heavy weights. It's all about finding a weight and repetition range that feels challenging to you, as well as moving slowly and intentionally so that you increase the time your muscles are under tension, which is a great way to build strength over time.
