No federal taxes were taken out on my W2 and I didn’t think it was wrong until I had already filed

[JC0412]

This is only my second time filing my taxes. I filed through turbo tax, then went through my county, and thought I was set. However on my W2 it showed an empty box rather than a number where it shows the amount of federal taxes payed. I just assumed it was an odd “just the way taxes work” thing, and filed my taxes. Assuming that since it came through my former employer it was fine…. When I told my mom about it she thought it was strange. 
I’ve concluded that I should definitely not have filed my taxes without double checking, but I’m working to fix my mistake. I’m trying to get into contact with my former employer, so I can get a corrected W2, but what else do I need to do? 
Will I be in trouble because I filed an incorrect W2? How do I file the correct one? Is there a different correction process for the federal/state level and the county level? 

[MaryK4]

If your former employer did not withhold taxes, you will not need to make any adjustments.  You may want to check on your paycheck stubs, the amounts would have to reported there as well.  When you are hired, you complete a W4 to indicate if you are exempt from withholding.  

You will only get in trouble if you report a W2 with information that is not on the W2 you received; since you entered what you have you have done nothing wrong.  You can wait and see if a W2C is issued- then you can amend your tax return to make the corrections. Your employer is required to withhold unless you indicate that you were exempt, so if you owed taxes, you ay want to update the information with your employer.  (It is always a good idea to review this information periodically and make any adjustments as needed).  Some states use the same W4 information, but some have a specific state form.  Once again, you should fill one out when you start a new job and review as needed.

[VolvoGirl]

Your W2 is probably right.  Did you have a tax due when you filed your tax return?  If your income was low and you don't owe any tax on it then it was probably right the employer didn't take out any  tax withholding from your pay.  Do your paychecks have any federal income tax withholding taken out in addition to the SS & Medicare?