My car is Toyota Corolla Hatchback 1992, 1

My car is Toyota corolla hatchback 1992, 1.3 cc. When I start driving like 30 km/h, my car shakes, its like when u drive with a damaged tire, but my tires are good, and when I sped up like 50km/hr, the shaking will stop, I already checked the tire and balance the wheel but it is still the same, I also changed my wheel and tire, but still same, I m so confused, and another thing my car wheel size is 195/50R15, and when I gut at the speed of 100km/hr the string shakes and also u well feel it if you were also a passenger, Please help me.
Thank you
regards
Ephrem Abebe