There are some easy ways to help you build credit while being responsible. You might want to consider one of these two options (or even both) for rebuilding your credit.
Answers to your questions in order:
1. You might want to consult someone more knowledgeable, like a bank employee
2. Get a secured credit card. This is different from a normal credit card or a prepaid credit card. Prepaid credit cards are like debit cards. With a secured credit card, you can get a credit card worth 50% to 100% of your deposit. Your deposit gets used if you default on paying what you owe. Prepaid credit cards do not build your credit, but secured credit cards do. Here is a page that you can use to find a secured credit card based on your personal preferences.http://www.nerdwallet.com/secured-credit-cards
3. Go to a bank and tell them that you want to deposit $1,000 into a certificate of deposit for 6 months and that and the same time you want to borrow $1,000 to be paid back over 6 months and use the certificate of deposit as collateral. No bank will turn this down as there is no risk for them and they come out even if you never pay and ahead if you do. On your side, your credit score improves. You can do this at multiple banks at the same time to improve your credit rating faster (so long as you have the income to be paying them all off concurrently).
Also, I read somewhere that you should keep purchases on your credit card around 10% or so of the credit card's max for credit-building purposes. (Not sure how true this is, but I read an article on it somewhere)