Hi @Pascale2 ,
Here is a link which explains when you are qualified to claim head of household status. From what you have stated in the question, you support your unemployed daughter who lives with you. You qualify to claim head of household since she is a "qualifying person".
Do I qualify for Head of Household in 2022?
Your second question is how you can fill out the W-4 for your new job so you do not owe taxes when you file your tax return.
Below is W-4 Calculator for 2023 which will help you determine that.
W-4 Calculator 2023