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When i made the full bridge rectifier i dident understood one thing, do you need a load or will it work fine whithout it.

No load can describe a Giga-ohm or a Tera-ohm resistance, or a Zero ohm resistance. In the case of a zero ohm resistance, you are likely exceeding the maximum allowed current in the diodes or in the wires.

Be careful if you are unsing a desktop scope to see the voltage curves: the scope ground is the ground of the electrical domestic distribution network (through the plug supplying the scope with electrical energy) and the "ground" aligator wire of the probe has to be at THAT ground, unless you want to buy a new scope, or, if you are lucky, just a new probe. Hand held scope, of differential probes can be placed anywhere on the circuit, though (as long as there is only one such probe used at a time, check with the supplier if you have more than one such probe available).

Be very careful using a bridge rectifier on your domestic 120vac utility supply. The ground jumps back and forth between the + and - outputs so if you connect the "ground" of any device to either + or - you can get quite a shock from that device; 60 pps at 170v peak.

Re your "load" question: The bridge rectifier produces full wave rectified dc voltage no matter what load is on it. Of course if the load is low enough ohms that the load current is greater than the bridge diode rating they will burn out.

Thank you, i will buy a step down transformer so i can make it safely

It is kind of a rhetorical question as the instant you go to measure the output you are, in essence, putting a load on it. I have only ever used bridge rectifiers with a load, even just a 1000 ohm resistor.