The account is given from the perspective of Creation Itself, the heavens (including High Heaven) and the earth. Thus it was almost like a song or a poem with more than one voice. Verses one and two are just the set up and (https://earlygenesistherevealedcosmology.blogspot.com/2017/11/thesis-7-heavens-and-earth-were-created.html) are before the first day. Thus verse 3 on is is an account of God’s work ON the heavens and the earth, which He created in verse one.
The days (yom) are like “work days” to us. Each begins when God speaks and each ends when He says it is suitable. After the mid point of the third day the realm above and the realm below are separated. They do not equally respond to God’s Word. It happens quickly and perfectly up there, down here, it is a process and takes a loooong time and sometimes God Himself must help creation down here along.
That the phrase “evening and morning” is used without definite articles shows it is not a specific day, indeed a literal view of the phrase would be a night, not a day. It describes creation unwinding into darkness and chaos on its own, but the Word of the Creator brings illumination and order to whatever aspect of creation He is speaking to.
Regarding the creation of man, I have to much to say to even address here, but this is not just a single person being described being created but God fusing with humanity in the heavens into the Image of God. A special human is made on earth almost as an echo of that event in the heavens (each of these days except day five describes things happening in High Heaven and on earth with the same language, a double meaning). And large numbers of humans are made on earth who are not yet in the image of God but He intends to make (a process) them in His image.
The seventh day you mention is an awe-inspiring wonder. That none of these days were literal 24 hour days in both realms is shown in that scripture, if one looks closely enough, teaches that the seventh day in Genesis one did not even BEGIN until after Christ was on the cross. How could this be? Hey, God’s Word, He can work it out…