How much time it takes to build body in gym?

There's no single answer to this one, mate. It really depends on heaps of things. Think genetics, diet, and how consistently you train. You'll likely feel stronger within a few weeks. But for noticeable muscle growth that others can see, you're looking at a solid 3 to 6 months of proper training. For a serious transformation, it's more like a year or two of dedicated effort. Just remember, sorting out your diet and getting enough sleep are just as crucial as the work you do in the gym. It's a marathon, not a sprint.