Getting your race car in and out of a trailer will require a ramp. Most trailers have some sort of built-in ramp. In some cases, the ramp may be stored under the trailer bed, fixed in place with pins that can be removed so that the ramp can slide out for use. Other ramps may stand upright at the back of the trailer until needed, at which point they can be dropped into position. Some trailers, commonly used by towing companies, have hydraulic tilting beds, where the entire bed can lower into position to form a ramp, then return to a level position for transport. These types of trailers are extremely useful, but they're also quite expensive.
Many open trailers come with a "beavertail," a downwardly curved portion at the rear of the bed that effectively provides a ramp for your car. (This can be used in conjunction with some of the ramp types listed above.) Some closed trailers even have a beavertail rear door, which converts into a ramp when opened. In some cases it may be necessary to raise the front of the trailer with a hydraulic lift in order to lower the beavertail to the point where the car can be driven on to it.
Once the ramp is in place, the car can be driven on board or it can be hauled on board with a winch. The winch, which can be attached to a secure portion of the car, is usually operated by a motor. And once the car has been raised onto the trailer bed, it must be carefully positioned. Placing the car too far forward or too far to the rear can affect the trailer's stability. And, if the trailer is an open one, care must be taken that the tires are solidly on the bed and not hanging over one side.
Now that you have a trailer and your car is securely on board, there's only one more thing to worry about: finding an appropriate vehicle to tow it with.