to cc JB
Padded shorts/bibs/tights are essential if you plan to start doing longer rides.
Gloves and glasses are also essential IMO - regardless of weather.
Helmets are a personal thing. I wear one, some don't. If you do get one make sure you get one that fits and conforms to a standard.
If your not used to road bike geometry and riding in general I'd stick to the flat pedals until your confidence increases, after that if you want to go clipless then the world's your oyster. In the meantime
THIS thread will answer all your clipless questions for you.
Don't forget as well you need to be self sufficient in terms of repairs when you're out, and therefore you'll need things like spare tubes, pump, tyre levers, patches, chain splitter, spare missing link for chain, multi tool etc. I also carry an old rag, (with my multi tool in it, and some nitrile gloves to keep things clean), oh and some loose change as well, just on case. FWIW I also wear dog tags on the bike with emergency information on them, or you can always program an I.C.E. number into your phone.
Get a track pump as well for at home use. Correctly inflated tyres are one of the best puncture avoidance methods you can use, and 'normal' pumps just don't cut the mustard.