The chances of getting anything worthwhile from the seeds of apples or pears are vanishingly small, but maybe worth it for the interest. Normally they shoot in the spring after a period of 'vernalisation' or cold treatment. Just pot them on carefully and plant out in a patch of spare land in the autumn or next spring. After four or more years (our crab apple took six years!) you may have a tree large enough to see what the flowers and fruit will be like.
What you could do more valuably is use your pear seedlings as rootstocks and then graft on to them a good named pear variety when they are large enough in a few years' time.
I found doing a 'saddle graft' was the easiest method for an amateur.