Well, I think there are some \r \n missing in them and also, the AT+CIPSEND is being sent the wrong length.
You should try sending it again, like this:
AT+CIPSEND=43\r\n
GET /test.php?Data=2\r\nHost:192.168.1.13\r\n\r\n
Just hit enter to send \r\n and ensure that you select "Both NL & CR" in your serial monitor. And of course, you will need to hit Enter twice at the end.
So, here I am sending 2 as my value and hence, after subtracting the 1 for every \r & \n from the size o your GET(), i.e., 49 will become 49 - 6 = 43.
Try to send the value directly from the URL and make sure that your PHP script is error-free and working.