Welcome to the RV Forum and RVing. You asked about sequence and there isn't any one sequence. Some of it depends of the RV. For example, we're supposed to keep our engine on until the air tanks are full, then turn it off, put out the slides, and then level. Other RVs from the same manufacturer are supposed to do it differently.
What's important in the desert southwest is how hot it is outside. If we're on the road and it's over 90-100 degrees outside the most important thing is to plug in the electric so the roof air conditioners can be turned on. I also put out the patio awning (it's electric and push button so easy) if Jerry will be getting into the underbay on that side. That's another comfort item so he's not in the sun as much as without the awning. After those comfort items we worry about hooking up water and sewer, leveling, putting out the slides, and otherwise getting set up. For hygienic reasons, Jerry prefers to handle the fresh water hoses before the sewer hoses. In reality, most of it is a routine that is a logical sequence and you can remember. It's good to make a list initially so you don't forget anything, but once you have the routine you won't need the list.
It's also good to have a list for leaving the campground. Always do it in sequence to make sure you're not still hooked to a utility post, that your antennas are down, your step is in, and everything inside is stowed. Always do your leaving tasks in the same order because it's easy to forget something, especially if you're interrupted. Before leaving we BOTH do a walk-around to check that everything is properly hooked, stowed and unhooked. That can include open windows that should be closed, a TV antenna that is not stowed, etc. Don't laugh. More than one person has pulled out of a campsite with a water hose still attached to spigot!
Most important of all - don't stress over it all and enjoy the experience. It all gets easier with each excursion.
ArdraF