1. Probably. If they are playing only to make you happy, chances are it won't be a good game for anyone. It's hard to get that accomplished at your age though. Ask your parents if there is a hobby shop nearby that sells books for the game, see if you can go and browse the place to see if they have games scheduled. Ask the clerk behind the counter if they have games run there, and if he'd be able to join if they do. Maybe your dad will prefer to give you a ride there rather than play.
2. I would say, sure, why not? It will give you experience. If you purchase the pre-made adventures, you'll be wasting your money in my opinion. You're young, if you can take the time to make them, go right ahead.
3. Thats up to you and those you play with. It's not necessary by any means. If it matters to you, it matters to you, if not, then it doesn't matter at all.
4. A single session game would be best at first to get everyone used to the rules, a test run if you will. After that, slowly build up how long you can run the game.
5. I'm sorry you bought the basic game. The rules are different from the standard version, and it's only good for 2 levels from what I heard. It's a good way to introduce people, but only if you get it for free.
Since you have computer access....
The Hypertext d20 SRD (v3.5 d20 System Reference Document) :: d20srd.org is a great place to look up rules to use. It's free, and gives you almost everything from 5 books. The few things you'll want out of the DM guide that aren't there are things like gold per level for characters and NPCs, and experience progression charts.
Hope that helps.