I turn off my data on my phone because it said we almost used 90% of our data. So when I am in my car and I send a message it's green, why is that? And once I am connected to wifi I started getting all response to the text message I sent. Is there anyway I can fix it without turn back on my data?
The messages being green means that they are SMS and not data (ie not iMessages).
Make sure in your Settings that under "Messages" you have "Send as SMS" turned on.
Also ask the other iPhone users who are texting you to do the same thing.
Otherwise, you will not get iMessages when not connected to data.