Start here, check if any of your emails or other accounts have been compromised.

https://haveibeenpwned.com/

(Just because your email shows up here does not mean it's been hijacked, it just means the way to get into that particular email or account was leaked at one point via a data breach)

If you have been compromised, to the best of your ability change the information, security questions, and passwords to those accounts.

Additionally, if you can, keep record of the following;

• The emails that were compromised.
• The passwords that went along with them.
• The security questions you used to secure those accounts.
• The profile information that was available on those accounts.

This will give you some idea of what data of yours could be floating around if they indeed accessed your accounts via data breeches.

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Do a free credit report.

https://www.consumer.ftc.gov/articles/0155-free-credit-reports

This will allow you to see if you have been the subject of identity theft on a financial level. Things like a low score or strange details that you are sure have no connection to you.

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These are the easiest things you can do which cost nothing.

If you are only looking to check your voter registration, you could try

https://www.usa.gov/voter-registration

But I'm unsure of the process and if you'd be notified of other "you's" in other States.

Hope some of this helps.