No one else can look up your W-2's for you. W-2's come from employers; they issue them to you by the end of January if you were an employee. You can ask your employer for copies if you lost them or did not receive them for some reason.
And....you say you do not know when you last filed a tax return----you are too late to receive an income tax refund for any tax year earlier than tax year 2021---any earlier ones have been forfeited. But if you owe tax due, you owe it forever with late filing penalties and interest.
W-2's come from employers. There is not a federal or national website that provides W-2’s.
Some employers have payroll sites that will have your W-2. You might need to phone, drop in, email and/or snail mail an old employer to make sure they know where to send your W-2.
https://ttlc.intuit.com/questions/2561916-how-can-i-get-a-copy-of-my-w-2
Other ways to get W-2’s:
You can get a wage and income transcript from the IRS: It will not show the actual W-2, 1099’s, etc, but will show the income information the IRS received. It will not, however, show your state information. It will only show the federal information.
https://www.irs.gov/individuals/get-transcript
Pay Social Security $126 per tax year for your W-2’s.:
https://faq.ssa.gov/en-US/Topic/article/KA-02501
What if I do not file my tax return?
https://ttlc.intuit.com/questions/2572308-what-happens-if-i-don-t-file-my-taxes
Each tax year has to be filed separately using the forms for the specific tax year. They cannot be combined in any way--do not even put them in the same envelope when you mail them.
It might be better for you to seek local paid tax help in a situation when you are several years behind in filing your tax returns. Do you even have all of the documents you will need to enter and show your income—like your W-2’s and any 1099’s?
You cannot change the tax year. The current online program is for 2023 only. Only a 2023 return can be prepared online and only a 2023 return can be e-filed.