your employer was supposed to file copies of the W-2 with the Social Security Adm back in Feb or earlier. The SSA transfers the federal data to the IRS and the state data to the states.
if the employer has transmitted the info to the SSA, you can get a transcript of the federal data from the IRS, for state data you would need a copy from the SSA.
are you sure that your "employer" treated you as an employee rather than as an Independent Contractor (IC)? if not, then they should have sent you a 1099-misc. this too would be available in IRS transcript.
https://www.irs.gov/site-index-search?search=transcript&field_pup_historical_1=1&field_pup_historica...
it's important to determine employee/ IC status. if an IC you'll owe self-employment taxes in addition to income taxes. as an employee, you would see medicare and social security taxes deducted from your paychecks.
if an employee you can use form 4852 as a substitute for the W-2. your employer will be contacted.
