How can I get numbers and letters to send text.

HOW TO VIDEOS

You should have a manual for your phone, but if you don't try this, which i found on the web in google:

How To Text Message On A Cell Phone
The process of sending a text message will vary by phone, but there are some basic principles that apply to most mobile devices for texting.
Here is a walkthrough on how to send a text message to another person's cell phone on my older model LG cell phone, which isn't a new smart phone with handy features for texting like a full keyboard.
1. Go to phone's main "Menu" and select "Messaging" option.
2. Select "Text Messages" (some might see "Send SMS") and then select "Write message."
3. Now your ready to type your short message. Enter words by typing the corresponding letters on each numeric key on your phone's keypad. Type the key for each letter repeatedly and quickly until the letter you want appears.
4. To type a new letter, simply hit another numeric key. If the next letter that you need is located on the same key, wait a few seconds for the cursor to move.
5. To type a space, press "0." To toggle between capital letters, lowercase and numbers, hit the "#up arrow" button. To type a special character, hit the "*" button.
6. Once your message is all typed out and ready to be sent, typed, use the "options" or "menu" button. The phone will prompt you to enter a phone number or an e-mail address to send the message to and select "Send."
If you have an iPhone or BlackBerry with keys to help you type messages, you'll be able to tap out and send messages fairly quickly. For older model cell phones, as you send more text messages, you'll grow more used to typing on the keypad and you'll get faster at texting.