Re: About the bill in the united states!
Bills can start in either the House of Representatives or the Senate. If a regular citizen wants to see a law, he or she starts by contacting his or her Senator or Representative.
The bill will start by being reviewed by a committee, who may think it's great and send it for a vote by the full Senate/House. Usually they will make changes. They may decide it doesn't even make it out of their review process to the main floor.
The entire House or Senate must vote on the bill. It then moves to the other body -- a House bill will be reviewed by the Senate and vice versa. Changes will probably be made. That means the two need to send representatives to work on a compromise bill that would satisfy them both. After both have voted on the changed version, it goes to the President for signature. If the President signs it, it becomes a law. If the President vetoes it, it does not pass. However, if (I think) 2/3 of both the House and Senate vote to pass it anyway, it can still be come a law. (That's what's called a "veto-proof majority.") The president can choose to do neither, and if so, it becomes a law anyway after a certain period of time.
I don't actually know how the President submits something to Congress if he wants a law - he may present it to the Speaker of the House. What's more likely is that he would meet with key Senators about his ideas and they would present the bill on his behalf.
The difference between the two bodies is that there are two Senators from every state, so each state is equal, but the House is based on population, so where there are more people, there is more voice. This compromise keeps things balanced so the little states don't get screwed but the big states can bring up issues important to them.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.