Abut to buy my first bike for general health and exercise.
Not using it for commuting.

New bikes come with No pedals, ringer/bell, reflectors.

Besides the basic essentials like:
1) helmet (which I still have from years ago....) do they have a 'sell by' date like motorcycle helmets which average 7yrs?
2) water bottle

what others should I consider buying?

Should I buy decent pedals with option of clip-in, did a quick search and there are ones that offer flat on one side, clip-in other
Lights....haven't even looked at those
Gloves? essential?

shoes, can I get away with regular exercise trainers?
Cycling shorts/pants? jeans is a bad idea right?