For the rack you need to find two points in your appartment to which you can connect the ropes. The distance between them should be as large as possible, but at least 4 meter. They must be able to endure quite high forces. They also have to be on ground level. Using a heavy cupboard is NOT safe. In the worst case, the cupboard falls on you.
I have always used doors for this. All you need to do is to find doors that are more than 4 meters apart on opposite sides of the same room. If the door opens away from you, you can simply lead the rope under the door, and connect it to a little block of wood that lies on the other side of the door. If the door opens towards you, then open it, and lie a pole in the opening, which is long enough, so that its ends will stick against the wall next to the door. The rope can be connected to the pole. You can also use a chair, or household stairs instead of the pole.
Instead of a door, you could also use tubes of the central heating, but only at a point where they enter the floor, or a wall. These tubes are not very strong and you should not impose hight forces on them far from their connections points. The water inside the heating is hot and dirty. It better remains in the heating.