Did a one time consulting job earned a couple thousand in addition to my full time job. What do I do?

The minimum amount for reporting by the person who hired you is $600, and is sent to you on a 1099 form, similar to a W2, but with no taxes taken out.
(The minimum amount for self employment income on your own is actually $400, last time I checked.)

You can just add it to your regular 1040 under misc income. That's if you don't want to itemize any expenses that you can claim while having done the consulting. That takes a Schedule SE and Sch C.

Do about what? As noted, the amount exceeds $600 so they are required to send you a 1099. The question will be how this affects your taxes due. If you are underwithheld, you may incur a penalty. So you should do an estimate of your tax liability and maybe make a quarterly payment.

I believe that there is no penalty for not filing quarterly the first year of contract or self employment income.

Joy is correct about the first year "safe harbor" for NOT paying thew quarterly estimated tax.

The amount of consulting income that you have earn to begin reporting it on your tax return is $1. Yes, that is right. You have the LEGAL OBLIGATION to report as little as ONE DOLLAR on your tax return.

That said, the amount that causes the "employer" to generate a Form 1099-MISC is $600.