How can I access the files in "/data/data" and copy them into memory card without root? Are there any way to access the files in /data/data and copy them into memory card? I do not have root access.
Without root access you have 2 options. Both options (may) allow you to access the files for a particular app, e.g. the folder /data/data/com.app.packagename.


If the application is debuggable you can use the run-as command in adb shell (more info about what adb is and how to install it can be found here)

adb shell
run-as com.your.packagename` 
cp /data/data/com.app.packagename/

If the application is not debuggable, you can use Android's backup function.

adb backup -noapk com.app.packagename


You will now be prompted to 'unlock your device and confirm the backup operation'. It's best NOT to provide a password, otherwise it becomes more difficult to read the data. Just click on 'backup my data'. The resulting 'backup.ab' file on your computer contains all the app's data in android backup format. Basically it's a compressed tar file. This page explains how you can use OpenSSL's zlib command to uncompress it. 
You can use the  adb restore backup.db command to restore the backup.