The first direct payment was made summer of 2020 and allowed qualifying individuals to get up to $1,200, married couples filing jointly up to $2,400 plus $500 for every child under the age of 17.
Many people didn't receive their payment because incorrect or outdated banking information or addresses were on file.
That stimulus payment was essentially an advance on your 2020 tax credit, so if you qualified but never received your payment, you can still get it. You just need to claim it on your tax filing for 2020.
As for filing prior to getting your W2, you should receive your W2 by the end of January and it wouldn't be a good idea to file before then as you may not have all the correct information. Also, The IRS will only start processing most returns on January 20, 2020, but will not start processing returns with the Earned Income Tax Credit (EITC) or Additional Child Tax Credit (ACTC) until mid-February 2020.
Answers are correct to the best of my ability but do not constitute legal or tax advice.**If this post is helpful please click on "thumbs up"**
Where was 1/20 posted by the IRS ? With the new 1040 delay and the second stimulus check to be issued up to 1/15 I doubt they will start processing any sooner than 1/25 this year even if they pull some test returns sooner.