I received a CP2000 notice. Does this mean I was audited? If not, could I get audited even after agreeing to pay? Is it possible to receive more than 1 notice like this?

A CP2000 is generated by the IRS computer when it detects missing income on your return.  It is what is referred to as a paper audit.  If the IRS is correct and you agree then pay the amount they calculated. lf you disagree then read the letter to see what your options are.

Can you be audited again on this return ... possibly.  Do you normally get 2 of the same notice on the same tax return ... not usually since they normally catch all the missing income on the first notice.  However if you know something is still missing it would be best for you to amend the return and make the corrections before the IRS catches the mistake. 

The IRS does not consider a CP2000 notice an audit, but rather a correction of your return.

They have procedures to avoid "repetitive audits" but as they don't consider a CP2000 notice to be an audit they don't apply, and you still could go through an audit at a later date.

A CP2000 may be generated when the AUR computers erroneously compare payer information and a return.  Fir example, a computer-generated CP2000 and SNOD both of which state that the taxpayer reported $1,520 from payer T for Year 2016 as Qualified dividends, failed to report the same $1,520 as Taxable dividends from payer T for Year 2016 and claims 2016 tax is due at the Ordinary dividend rate on the $1,520 notwithstanding the payment of tax at the Qualified rate on the same income. AUR computers have "issues." IRS knows this.