How can i use do and have

Do - is used as a helping verb in simple present tense when there is a verb present in the given sentence with I, we,you,they,plural subject. For ex:- Do we go? I don't do it. Have - is used as a helping verb in present perfect tense with I,we,you,they, plural subject. Ex:- I haven't done this work yet. Have they had lunch? It's also used to show the emotion of present possession related to anything. Ex:- We have an old house. Don't I have a new watch?