You usually earn the instrument rating in the same, or a very similar aircraft to what you earn your PPL in. After PPL and IR training, you'll probably have logged about 100 hours.
After that, you'll spend about 100 hours building cross-country time in a similar aircraft. If you can afford it you might start flying more powerful and complex single engine planes with controllable propeller and retractable gear. You need a minimum of 10 hours in such aircraft, during which time you'll be practicing various commercial pilot flight maneuvers to pass the single-engine commercial pilot flight test. (see here, starting on p27: http://www.hsvwings.com/Pvt-Com%20Maneuvers.pdf)
After that, you'll transition to light multi-engine trainer but most people cannot afford more than 10-20 hours in them. You'll probably fly just enough in one to be competent to pass the multi-engine commercial and instrument flight tests.
By this time, you'll have logged somewhere between 200 to 250 flight hours and will have spent somewhere between $50,000 and $80,000 (USA prices), depending on where you train and what you fly. Only then, if you have the money, could you get an opportunity to do some training in a small jet or turbo-prop aircraft, probably for another $10,000 to $20,000. Most of it will be in a simulator and you might get 1 or 2 hours in an actual aircraft.
Finally, because you won't have enough flight time to be competitive for the vast majority of flying jobs, you'll realize that you need to spend another $10,000 or so to earn your single, multi-engine and instrument flight instructor certificates so you can get a job as an instructor at a flight school, teaching new students how to fly the same small, piston-powered airplanes you trained in yourself.
After a couple years of that you'll finally have enough flying experience to get a shot at flying something larger, perhaps at a regional airline or smaller cargo company, or charter company. This is where you'll most likely get your first opportunity to fly a medium-size multi-engine plane, a turboprop or smaller jet aircraft. The company that hires you will provide the training in the airplanes they fly. In return, you'll be paid ridiculously low wages.
From the beginning of flight training to this point, plan on it taking 5 years. Not what you expected? Get used to it, this is what most civilian-trained pilots face around the world.