First long-haul flight… tips for sleep/jet lag?

I’m doing my first international, long-haul flight in a few days, and it’s for a short trip. Really nervous about jet lag, sleep, what to do on the plane etc.

I leave Los Angeles on Saturday, 4/25 at 2:30pm PST, and arrive in Paris on Sunday 4/26 at 10:45am local time.

I depart Paris on Wednesday, 4/29 at 9:15am and arrive at 11:40am PST back home.

I wouldn’t have done such a short trip for my first time but it’s my grandma’s last trip out of the country and my first, so I wanted to join her. She’s flown internationally more times than I can count and she doesn’t need much sleep, so she’s not concerned. She says to just take a short nap when I get to Paris and I’ll be fine.

I’m excited to see Paris and I know it’ll be fun, but I am having a LOT of anxiety about:

Being jet lagged throughout the trip and being destroyed when I get back home. I don’t want to feel out of it for days but I can see myself having that experience. Do I even try to adjust to local time in Paris for such a short trip?

Being on a plane for so long. Like I can’t even conceptualize having to be on a plane for almost 12 hours. What do I even do? Sleep? Stay up?

When do go back to work. I called out Thursday 4/30 to be safe, do I need to do Friday 5/1 as well?

Can anyone help me out here?