Going from using admin account to standard user

Your second account will not have access to the main account's home folder.

There is, however, a much simpler approach.

1. Make yourself a new admin account - call it whatever you want the admin account to be called.

2. log out of your own account and into the admin account. Go into account prefs and demote your existing account to standard (simply uncheck the 'allow user to administer this computer' check box).

Job done.

The advantage to this is that you don't have to move your data and you get to keep your existing short name (changing the short name on an account is a very bad move - it's not permitted by the system without a lot of hacking about).