Hello & welcome!
No such thing as a daft question!
Commuting is great!

Winter or summer, it was often the best part of my day!
Your questions have been pretty much covered above. I'd echo (loudly) the suggestion to drop the backpack. I used aldi/lidl panniers (just one).
I'd eat as normal then have a snack when I got to work.
A couple of other things to consider....
A decent lock, especially if work security is lax. No bike, no commute!
Puncture fixing confidence! Murphy's law and all that.
Lights.
Make sure you're comfortable on the bike!
Give yourself lots of time - a relaxed, "smell the roses" ride is more enjoyable than a race - at least to me.
Look for a decent route, even if a little longer. Sometimes, one route will be better than another depending on weather.
https://cycle.travel/ is a great route planner for quieter roads.
24 miles every day is not nothing! On a similar length commute I "broke myself in" starting 1 or 2 days and slowly building up.
I used to stop and take photos on my commute. Over a year I had a record of particular places through the season, a nice record to have and a bit inspirational.
When I finally got a gps unit I started recording rides and competing against myself on Strava. It took a few weeks to cop on but I completely lost the enjoyment of my commute. I much preferred the relaxed, look around commute. Turns out I wasn't much slower. (That might just be me!

)
On morning commutes I'd vary my departure time depending on weather. Sometimes it was better to get ahead of a downpour and relax in the canteen.
Going from zero to 24 miles per day is a big jump and will have great benefits. It may not be easy though. It's ok to not enjoy it all the time - the good thing is you'll have lots of time to think about how to make it better.
Good luck!