Louvre arrival time

I was going to recommend the "Lion Gate" entrance, where (assuming it is open) you can just show up and buy a ticket within a few minutes; we waited maybe 5 minutes c. 11 AM in early June. However, the author of the linked recommendations says that if you have an advance ticket, you can skip the line at the pyramid entrance.

https://theparisitinerary.com/what-you-really-need-to-know-about-the-4-main-louvre-entrances/

The last two times I was at the Louvre there were three lines at the Pyramid. Facing the Pyramid, the line to the Left was for those with a Musuem Pass. To the Right were two lines, one for those with a reserved ticket in hand and to the Right of that those waiting to get into the Louvre to purchase a ticket. Everyone goes through the same security station once entering the Pyramid and then head down a level to the ticket windows/kiosks and museum proper. There were images posted on stands near the lines and staff were present to make sure people got into the correct line.

As for the time to show up for the time ticket I am not sure, the length of the line for reserved tickets will play a factor, the website states: "It is valid only for the chosen service, date and time. It is not a queue jump but gives access to the pyramid within half an hour of the time shown on the ticket. If the holder of the print@home ticket does not arrive within the allocated time slot for admission to the pyramid, they are subject to the same admission and waiting conditions as visitors without tickets".

There is a below ground entrance, but I am not sure if you can use it with a reserved ticket. With the Pyramid behind you, across the street you will see the Arc de Triomphe Carrousel, there are stairs to the Right and Left that head below ground. There is an entrance to the museum there as well.

I think (and I repeat think) you can use the underground carousel entrance with a timed entry ticket. Security lines are usually shorter there.