It took me a good few months of small adjustments to the seat,(and a change of seat!) to get it spot on. It will happen!
My younger daughter (19) rides (the eldest daughter, (28) rode for the Army as part of her job - mounted musician).
She always wears hoodies and jodhpurs as that's what she finds the most comfortable!
I ride in a vest top in the summer...cooling and comfy!
For the autumn I use a wicking top (runners top, a size bigger, 'cos I like them baggy) or a MTB top. I rarely use a fitted one now but I like the pockets!
I cycled through all of last winter, minus January and some of February, and found a micro fleece and a lightweight jacket ideal.
Saying that, we're a hardy bunch here in Scotland