1. $1400 round 3 COVID stimulus, unless your income is above the phase-out trigger.
2. $3600 child tax credit, unless your income is above the phase-out trigger.
3. If single, may allow you to qualify to file as head of household and pay a lower tax rate.
4. If you paid for day care to watch the child so you could work (and your spouse if married), you may qualify for the Child And Dependent Care Credit.
5. If you are lower income, you may qualify for Earned Income Credit.
In all cases, the child must have a social security number for any tax benefits. Don't file until you get the SSN, even if you have to wait. If it will take longer than April 15 to get the SSN, be sure to file for an extension. Don't plan to file without the child and then file an amended return when you get the SSN. You need to file an original, on-time tax return that has the child's SSN.
Also, unless there is a custody issue with parents who are divorced or separated and sharing custody, you will answer that the child lived with you all year. This is the correct answer for a newborn to claim the correct tax benefits.
