If you want to open a test account for Stripe they make this a very easy process.
1. Go to https://stripe.com
2. Click sign in, top right corner
3. Then click; Don’t have an account? Sign up
4. On this page click "skip this step"
5. You will greeted by “Welcome to Stripe. Just click go straight to dashboard
6. At the top of your dashboard you will see: “If you'd like to save this account, please provide an email and password. Save account” Just click save account and you will be asked for an email and password.
7. You now have a full test account.
8. Top right go to the drop down your account and select “account settings” here you will see a link to get your API keys.
For testing purposes you can go to this link which gives you all the test numbers for testing all responses.