Welcome to the Forum,
There's good news and bad news based on your comments.
First, the bad news. As a US citizen (often referred to as an Accidental American in your case) you're required to file an annual US tax return. You'll need to become compliant and not just ignore it. Become compliant involves using an IRS program - most likely Streamlined Foreign Offshore Compliance. You can find details here:
https://www.irs.gov/individuals/international-taxpayers/streamlined-filing-compliance-proceduresMany of us have been through this process, i can seem daunting, but for many with simple affairs, it's not that bad.
You'll have to file 3 years of tax returns (2018 - 2020) that are now considered delinquent - which you do as part of the Streamlined process. Depending on your cash/bank situation you may have to file what are known as FBAR's going back 6 years - but to be honest, it may not affect you.
Now the good news,. You won't be taxed by the US on your child benefit, so don't stress on that account.
Now the really good news - once you've sorted out your tax returns and are compliant, most likely you'll be entitled to Stimulus payments from Uncle Sam - totalling $3,200 per eligible adult (which you should be one).
Hopefully the above will help you - start by reading the link to the IRS website to understand a little more. There are others on the forum who will be able to guide you more and get you through the process - if your circumstances are simple, you shouldn't have to part with large amounts of cash to professional advisors - again, provided your circumstances are simple.