If you have only W2 income ("W2" is the name of the form the employer reports your income and tax witholding on) and no unusual other credits or deductions, then US tax filing is very simple. It is not much more than:

Taxable income = Total income - Standard deduction

Look up tax due in a table.

Subtract taxes already witheld, pay (or refund) the difference.

In most states you also have to file, but this is normally just transcribing a few totals from your federal filing and then computing the state tax due, normally just a simple percentage multiple.