I am quite concerned with all these very very basic level questions. If you don't know this stuff then it does not bode well for the much more complex stuff of getting the actual chips wired up and programmed.
To be honest, in my opinion the hardest part is to know what components you need. The programming shouldn't be that difficult because I can't that much wrong just toggle the LEDs off and on. Regarding the wiring: if I stick to the schematic I should be able to manage this.
If I get a lower voltage it wouldn't harm my project, would it?
Yes it would.
Really? Why? If Ill buy this part is there an easy way to check wether this part has a high resistance?
Also I looked up for a USB cable with open wires on the other end, but didn't find anything. In an early post you mentioned to cut an USB cable. Would the problem be solved if I just get an USB cable and cut it like this:
I'm really sorry for bothering you for so long, but I hope this is the last problem to solve.