Hi RRR
Just started on the road myself.
I’ve a seat pack for the essentials and have one roadie type shirt. The 3 big pockets work. Also the long zip is very useful.
Currently using some inner shorts as ‘lycra’, it is better than proper MTB shorts, ‘honest’.
MTBed on flats for past 5 years, using Shimano 105 SPD setup on road bike, you’ll soon get used to it.
Running a 105 Compact double drive train with the biggest cassette it will take at the back…my first road rides were in the dark peak, you will be walking unless you have a triple setup (and be looked on as a ‘faggot’ etc.)
Still keeping the peak on my helmet, keeps the rain off my specs 😉
It is a different type of pain…
…but strangely enjoyable.
Good luck!