if you only get paid by Google adsense then no need to create freelance contracts, unless you have clients.
I suggest you provide your LLC formation papers, US tax, tin or EIN number (if you have), a print out of the Google adsense page showing your latest payout history. If you receive an email every time google adsense paid you, print those too. And bank account statements reflecting those payments from adsense. Write yourself a letter of employment that you own the company and are able to work remotely. There were a few good examples of employment letters in this group (or ask chatgpt).
if you create freelance contracts make sure you also have invoices handy and transactions on your bank account that match the invoices. Google adsense payment should be accepted. Maybe also print the payment history from the adsense page and once again show the incoming payments on your bank account.